EntryUtil

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

public abstract class Entry {
    public static final String[] ID_PROJECTION = { "_id" };

    public static interface Columns {
        public static final String ID = "_id";
    }

    // The primary key of the entry.
    @Column("_id")
    public long id = 0;

    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.TYPE)
    public @interface Table {
        String value();
    }

    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.FIELD)
    public @interface Column {
        String value();

        boolean indexed() default false;

        boolean fullText() default false;

        String defaultValue() default "";

        boolean unique() default false;
    }

    public void clear() {
        id = 0;
    }
}


/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.text.TextUtils;

import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Field;
import java.util.ArrayList;

public final class EntrySchema {
    @SuppressWarnings("unused")
    private static final String TAG = "EntrySchema";

    public static final int TYPE_STRING = 0;
    public static final int TYPE_BOOLEAN = 1;
    public static final int TYPE_SHORT = 2;
    public static final int TYPE_INT = 3;
    public static final int TYPE_LONG = 4;
    public static final int TYPE_FLOAT = 5;
    public static final int TYPE_DOUBLE = 6;
    public static final int TYPE_BLOB = 7;
    private static final String SQLITE_TYPES[] = {
            "TEXT", "INTEGER", "INTEGER", "INTEGER", "INTEGER", "REAL", "REAL", "NONE" };

    private static final String FULL_TEXT_INDEX_SUFFIX = "_fulltext";

    private final String mTableName;
    private final ColumnInfo[] mColumnInfo;
    private final String[] mProjection;
    private final boolean mHasFullTextIndex;

    public EntrySchema(Class<? extends Entry> clazz) {
        // Get table and column metadata from reflection.
        ColumnInfo[] columns = parseColumnInfo(clazz);
        mTableName = parseTableName(clazz);
        mColumnInfo = columns;

        // Cache the list of projection columns and check for full-text columns.
        String[] projection = {};
        boolean hasFullTextIndex = false;
        if (columns != null) {
            projection = new String[columns.length];
            for (int i = 0; i != columns.length; ++i) {
                ColumnInfo column = columns[i];
                projection[i] = column.name;
                if (column.fullText) {
                    hasFullTextIndex = true;
                }
            }
        }
        mProjection = projection;
        mHasFullTextIndex = hasFullTextIndex;
    }

    public String getTableName() {
        return mTableName;
    }

    public ColumnInfo[] getColumnInfo() {
        return mColumnInfo;
    }

    public String[] getProjection() {
        return mProjection;
    }

    public int getColumnIndex(String columnName) {
        for (ColumnInfo column : mColumnInfo) {
            if (column.name.equals(columnName)) {
                return column.projectionIndex;
            }
        }
        return -1;
    }

    public ColumnInfo getColumn(String columnName) {
        int index = getColumnIndex(columnName);
        return (index < 0) ? null : mColumnInfo[index];
    }

    private void logExecSql(SQLiteDatabase db, String sql) {
        db.execSQL(sql);
    }

    public <T extends Entry> T cursorToObject(Cursor cursor, T object) {
        try {
            for (ColumnInfo column : mColumnInfo) {
                int columnIndex = column.projectionIndex;
                Field field = column.field;
                switch (column.type) {
                case TYPE_STRING:
                    field.set(object, cursor.isNull(columnIndex)
                            ? null
                            : cursor.getString(columnIndex));
                    break;
                case TYPE_BOOLEAN:
                    field.setBoolean(object, cursor.getShort(columnIndex) == 1);
                    break;
                case TYPE_SHORT:
                    field.setShort(object, cursor.getShort(columnIndex));
                    break;
                case TYPE_INT:
                    field.setInt(object, cursor.getInt(columnIndex));
                    break;
                case TYPE_LONG:
                    field.setLong(object, cursor.getLong(columnIndex));
                    break;
                case TYPE_FLOAT:
                    field.setFloat(object, cursor.getFloat(columnIndex));
                    break;
                case TYPE_DOUBLE:
                    field.setDouble(object, cursor.getDouble(columnIndex));
                    break;
                case TYPE_BLOB:
                    field.set(object, cursor.isNull(columnIndex)
                            ? null
                            : cursor.getBlob(columnIndex));
                    break;
                }
            }
            return object;
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    private void setIfNotNull(Field field, Object object, Object value)
            throws IllegalAccessException {
        if (value != null) field.set(object, value);
    }

    /**
     * Converts the ContentValues to the object. The ContentValues may not
     * contain values for all the fields in the object.
     */
    public <T extends Entry> T valuesToObject(ContentValues values, T object) {
        try {
            for (ColumnInfo column : mColumnInfo) {
                String columnName = column.name;
                Field field = column.field;
                switch (column.type) {
                case TYPE_STRING:
                    setIfNotNull(field, object, values.getAsString(columnName));
                    break;
                case TYPE_BOOLEAN:
                    setIfNotNull(field, object, values.getAsBoolean(columnName));
                    break;
                case TYPE_SHORT:
                    setIfNotNull(field, object, values.getAsShort(columnName));
                    break;
                case TYPE_INT:
                    setIfNotNull(field, object, values.getAsInteger(columnName));
                    break;
                case TYPE_LONG:
                    setIfNotNull(field, object, values.getAsLong(columnName));
                    break;
                case TYPE_FLOAT:
                    setIfNotNull(field, object, values.getAsFloat(columnName));
                    break;
                case TYPE_DOUBLE:
                    setIfNotNull(field, object, values.getAsDouble(columnName));
                    break;
                case TYPE_BLOB:
                    setIfNotNull(field, object, values.getAsByteArray(columnName));
                    break;
                }
            }
            return object;
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public void objectToValues(Entry object, ContentValues values) {
        try {
            for (ColumnInfo column : mColumnInfo) {
                String columnName = column.name;
                Field field = column.field;
                switch (column.type) {
                case TYPE_STRING:
                    values.put(columnName, (String) field.get(object));
                    break;
                case TYPE_BOOLEAN:
                    values.put(columnName, field.getBoolean(object));
                    break;
                case TYPE_SHORT:
                    values.put(columnName, field.getShort(object));
                    break;
                case TYPE_INT:
                    values.put(columnName, field.getInt(object));
                    break;
                case TYPE_LONG:
                    values.put(columnName, field.getLong(object));
                    break;
                case TYPE_FLOAT:
                    values.put(columnName, field.getFloat(object));
                    break;
                case TYPE_DOUBLE:
                    values.put(columnName, field.getDouble(object));
                    break;
                case TYPE_BLOB:
                    values.put(columnName, (byte[]) field.get(object));
                    break;
                }
            }
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public String toDebugString(Entry entry) {
        try {
            StringBuilder sb = new StringBuilder();
            sb.append("ID=").append(entry.id);
            for (ColumnInfo column : mColumnInfo) {
                String columnName = column.name;
                Field field = column.field;
                Object value = field.get(entry);
                sb.append(" ").append(columnName).append("=")
                        .append((value == null) ? "null" : value.toString());
            }
            return sb.toString();
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public String toDebugString(Entry entry, String... columnNames) {
        try {
            StringBuilder sb = new StringBuilder();
            sb.append("ID=").append(entry.id);
            for (String columnName : columnNames) {
                ColumnInfo column = getColumn(columnName);
                Field field = column.field;
                Object value = field.get(entry);
                sb.append(" ").append(columnName).append("=")
                        .append((value == null) ? "null" : value.toString());
            }
            return sb.toString();
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public Cursor queryAll(SQLiteDatabase db) {
        return db.query(mTableName, mProjection, null, null, null, null, null);
    }

    public boolean queryWithId(SQLiteDatabase db, long id, Entry entry) {
        Cursor cursor = db.query(mTableName, mProjection, "_id=?",
                new String[] {Long.toString(id)}, null, null, null);
        boolean success = false;
        if (cursor.moveToFirst()) {
            cursorToObject(cursor, entry);
            success = true;
        }
        cursor.close();
        return success;
    }

    public long insertOrReplace(SQLiteDatabase db, Entry entry) {
        ContentValues values = new ContentValues();
        objectToValues(entry, values);
        if (entry.id == 0) {
            values.remove("_id");
        }
        long id = db.replace(mTableName, "_id", values);
        entry.id = id;
        return id;
    }

    public boolean deleteWithId(SQLiteDatabase db, long id) {
        return db.delete(mTableName, "_id=?", new String[] { Long.toString(id) }) == 1;
    }

    public void createTables(SQLiteDatabase db) {
        // Wrapped class must have a @Table.Definition.
        String tableName = mTableName;
        Utils.assertTrue(tableName != null);

        // Add the CREATE TABLE statement for the main table.
        StringBuilder sql = new StringBuilder("CREATE TABLE ");
        sql.append(tableName);
        sql.append(" (_id INTEGER PRIMARY KEY AUTOINCREMENT");
        StringBuilder unique = new StringBuilder();
        for (ColumnInfo column : mColumnInfo) {
            if (!column.isId()) {
                sql.append(',');
                sql.append(column.name);
                sql.append(' ');
                sql.append(SQLITE_TYPES[column.type]);
                if (!TextUtils.isEmpty(column.defaultValue)) {
                    sql.append(" DEFAULT ");
                    sql.append(column.defaultValue);
                }
                if (column.unique) {
                    if (unique.length() == 0) {
                        unique.append(column.name);
                    } else {
                        unique.append(',').append(column.name);
                    }
                }
            }
        }
        if (unique.length() > 0) {
            sql.append(",UNIQUE(").append(unique).append(')');
        }
        sql.append(");");
        logExecSql(db, sql.toString());
        sql.setLength(0);

        // Create indexes for all indexed columns.
        for (ColumnInfo column : mColumnInfo) {
            // Create an index on the indexed columns.
            if (column.indexed) {
                sql.append("CREATE INDEX ");
                sql.append(tableName);
                sql.append("_index_");
                sql.append(column.name);
                sql.append(" ON ");
                sql.append(tableName);
                sql.append(" (");
                sql.append(column.name);
                sql.append(");");
                logExecSql(db, sql.toString());
                sql.setLength(0);
            }
        }

        if (mHasFullTextIndex) {
            // Add an FTS virtual table if using full-text search.
            String ftsTableName = tableName + FULL_TEXT_INDEX_SUFFIX;
            sql.append("CREATE VIRTUAL TABLE ");
            sql.append(ftsTableName);
            sql.append(" USING FTS3 (_id INTEGER PRIMARY KEY");
            for (ColumnInfo column : mColumnInfo) {
                if (column.fullText) {
                    // Add the column to the FTS table.
                    String columnName = column.name;
                    sql.append(',');
                    sql.append(columnName);
                    sql.append(" TEXT");
                }
            }
            sql.append(");");
            logExecSql(db, sql.toString());
            sql.setLength(0);

            // Build an insert statement that will automatically keep the FTS
            // table in sync.
            StringBuilder insertSql = new StringBuilder("INSERT OR REPLACE INTO ");
            insertSql.append(ftsTableName);
            insertSql.append(" (_id");
            for (ColumnInfo column : mColumnInfo) {
                if (column.fullText) {
                    insertSql.append(',');
                    insertSql.append(column.name);
                }
            }
            insertSql.append(") VALUES (new._id");
            for (ColumnInfo column : mColumnInfo) {
                if (column.fullText) {
                    insertSql.append(",new.");
                    insertSql.append(column.name);
                }
            }
            insertSql.append(");");
            String insertSqlString = insertSql.toString();

            // Add an insert trigger.
            sql.append("CREATE TRIGGER ");
            sql.append(tableName);
            sql.append("_insert_trigger AFTER INSERT ON ");
            sql.append(tableName);
            sql.append(" FOR EACH ROW BEGIN ");
            sql.append(insertSqlString);
            sql.append("END;");
            logExecSql(db, sql.toString());
            sql.setLength(0);

            // Add an update trigger.
            sql.append("CREATE TRIGGER ");
            sql.append(tableName);
            sql.append("_update_trigger AFTER UPDATE ON ");
            sql.append(tableName);
            sql.append(" FOR EACH ROW BEGIN ");
            sql.append(insertSqlString);
            sql.append("END;");
            logExecSql(db, sql.toString());
            sql.setLength(0);

            // Add a delete trigger.
            sql.append("CREATE TRIGGER ");
            sql.append(tableName);
            sql.append("_delete_trigger AFTER DELETE ON ");
            sql.append(tableName);
            sql.append(" FOR EACH ROW BEGIN DELETE FROM ");
            sql.append(ftsTableName);
            sql.append(" WHERE _id = old._id; END;");
            logExecSql(db, sql.toString());
            sql.setLength(0);
        }
    }

    public void dropTables(SQLiteDatabase db) {
        String tableName = mTableName;
        StringBuilder sql = new StringBuilder("DROP TABLE IF EXISTS ");
        sql.append(tableName);
        sql.append(';');
        logExecSql(db, sql.toString());
        sql.setLength(0);

        if (mHasFullTextIndex) {
            sql.append("DROP TABLE IF EXISTS ");
            sql.append(tableName);
            sql.append(FULL_TEXT_INDEX_SUFFIX);
            sql.append(';');
            logExecSql(db, sql.toString());
        }

    }

    public void deleteAll(SQLiteDatabase db) {
        StringBuilder sql = new StringBuilder("DELETE FROM ");
        sql.append(mTableName);
        sql.append(";");
        logExecSql(db, sql.toString());
    }

    private String parseTableName(Class<? extends Object> clazz) {
        // Check for a table annotation.
        Entry.Table table = clazz.getAnnotation(Entry.Table.class);
        if (table == null) {
            return null;
        }

        // Return the table name.
        return table.value();
    }

    private ColumnInfo[] parseColumnInfo(Class<? extends Object> clazz) {
        ArrayList<ColumnInfo> columns = new ArrayList<ColumnInfo>();
        while (clazz != null) {
            parseColumnInfo(clazz, columns);
            clazz = clazz.getSuperclass();
        }

        // Return a list.
        ColumnInfo[] columnList = new ColumnInfo[columns.size()];
        columns.toArray(columnList);
        return columnList;
    }

    private void parseColumnInfo(Class<? extends Object> clazz, ArrayList<ColumnInfo> columns) {
        // Gather metadata from each annotated field.
        Field[] fields = clazz.getDeclaredFields(); // including non-public fields
        for (int i = 0; i != fields.length; ++i) {
            // Get column metadata from the annotation.
            Field field = fields[i];
            Entry.Column info = ((AnnotatedElement) field).getAnnotation(Entry.Column.class);
            if (info == null) continue;

            // Determine the field type.
            int type;
            Class<?> fieldType = field.getType();
            if (fieldType == String.class) {
                type = TYPE_STRING;
            } else if (fieldType == boolean.class) {
                type = TYPE_BOOLEAN;
            } else if (fieldType == short.class) {
                type = TYPE_SHORT;
            } else if (fieldType == int.class) {
                type = TYPE_INT;
            } else if (fieldType == long.class) {
                type = TYPE_LONG;
            } else if (fieldType == float.class) {
                type = TYPE_FLOAT;
            } else if (fieldType == double.class) {
                type = TYPE_DOUBLE;
            } else if (fieldType == byte[].class) {
                type = TYPE_BLOB;
            } else {
                throw new IllegalArgumentException(
                        "Unsupported field type for column: " + fieldType.getName());
            }

            // Add the column to the array.
            int index = columns.size();
            columns.add(new ColumnInfo(info.value(), type, info.indexed(), info.unique(),
                    info.fullText(), info.defaultValue(), field, index));
        }
    }

    public static final class ColumnInfo {
        private static final String ID_KEY = "_id";

        public final String name;
        public final int type;
        public final boolean indexed;
        public final boolean unique;
        public final boolean fullText;
        public final String defaultValue;
        public final Field field;
        public final int projectionIndex;

        public ColumnInfo(String name, int type, boolean indexed, boolean unique,
                boolean fullText, String defaultValue, Field field, int projectionIndex) {
            this.name = name.toLowerCase();
            this.type = type;
            this.indexed = indexed;
            this.unique = unique;
            this.fullText = fullText;
            this.defaultValue = defaultValue;
            this.field = field;
            this.projectionIndex = projectionIndex;

            field.setAccessible(true); // in order to set non-public fields
        }

        public boolean isId() {
            return ID_KEY.equals(name);
        }
    }
}

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import com.android.gallery3d.common.Entry.Table;

import java.io.Closeable;
import java.io.File;
import java.io.IOException;

public class FileCache implements Closeable {
    private static final int LRU_CAPACITY = 4;
    private static final int MAX_DELETE_COUNT = 16;

    private static final String TAG = "FileCache";
    private static final String TABLE_NAME = FileEntry.SCHEMA.getTableName();
    private static final String FILE_PREFIX = "download";
    private static final String FILE_POSTFIX = ".tmp";

    private static final String QUERY_WHERE =
            FileEntry.Columns.HASH_CODE + "=? AND " + FileEntry.Columns.CONTENT_URL + "=?";
    private static final String ID_WHERE = FileEntry.Columns.ID + "=?";
    private static final String[] PROJECTION_SIZE_SUM =
            {String.format("sum(%s)", FileEntry.Columns.SIZE)};
    private static final String FREESPACE_PROJECTION[] = {
            FileEntry.Columns.ID, FileEntry.Columns.FILENAME,
            FileEntry.Columns.CONTENT_URL, FileEntry.Columns.SIZE};
    private static final String FREESPACE_ORDER_BY =
            String.format("%s ASC", FileEntry.Columns.LAST_ACCESS);

    private final LruCache<String, CacheEntry> mEntryMap =
            new LruCache<String, CacheEntry>(LRU_CAPACITY);

    private File mRootDir;
    private long mCapacity;
    private boolean mInitialized = false;
    private long mTotalBytes;

    private DatabaseHelper mDbHelper;

    public static final class CacheEntry {
        private long id;
        public String contentUrl;
        public File cacheFile;

        private CacheEntry(long id, String contentUrl, File cacheFile) {
            this.id = id;
            this.contentUrl = contentUrl;
            this.cacheFile = cacheFile;
        }
    }

    public static void deleteFiles(Context context, File rootDir, String dbName) {
        try {
            context.getDatabasePath(dbName).delete();
            File[] files = rootDir.listFiles();
            if (files == null) return;
            for (File file : rootDir.listFiles()) {
                String name = file.getName();
                if (file.isFile() && name.startsWith(FILE_PREFIX)
                        && name.endsWith(FILE_POSTFIX)) file.delete();
            }
        } catch (Throwable t) {
            Log.w(TAG, "cannot reset database", t);
        }
    }

    public FileCache(Context context, File rootDir, String dbName, long capacity) {
        mRootDir = Utils.checkNotNull(rootDir);
        mCapacity = capacity;
        mDbHelper = new DatabaseHelper(context, dbName);
    }

    @Override
    public void close() {
        mDbHelper.close();
    }

    public void store(String downloadUrl, File file) {
        if (!mInitialized) initialize();

        Utils.assertTrue(file.getParentFile().equals(mRootDir));
        FileEntry entry = new FileEntry();
        entry.hashCode = Utils.crc64Long(downloadUrl);
        entry.contentUrl = downloadUrl;
        entry.filename = file.getName();
        entry.size = file.length();
        entry.lastAccess = System.currentTimeMillis();
        if (entry.size >= mCapacity) {
            file.delete();
            throw new IllegalArgumentException("file too large: " + entry.size);
        }
        synchronized (this) {
            FileEntry original = queryDatabase(downloadUrl);
            if (original != null) {
                file.delete();
                entry.filename = original.filename;
                entry.size = original.size;
            } else {
                mTotalBytes += entry.size;
            }
            FileEntry.SCHEMA.insertOrReplace(
                    mDbHelper.getWritableDatabase(), entry);
            if (mTotalBytes > mCapacity) freeSomeSpaceIfNeed(MAX_DELETE_COUNT);
        }
    }

    public CacheEntry lookup(String downloadUrl) {
        if (!mInitialized) initialize();
        CacheEntry entry;
        synchronized (mEntryMap) {
            entry = mEntryMap.get(downloadUrl);
        }

        if (entry != null) {
            synchronized (this) {
                updateLastAccess(entry.id);
            }
            return entry;
        }

        synchronized (this) {
            FileEntry file = queryDatabase(downloadUrl);
            if (file == null) return null;
            entry = new CacheEntry(
                    file.id, downloadUrl, new File(mRootDir, file.filename));
            if (!entry.cacheFile.isFile()) { // file has been removed
                try {
                    mDbHelper.getWritableDatabase().delete(
                            TABLE_NAME, ID_WHERE, new String[] {String.valueOf(file.id)});
                    mTotalBytes -= file.size;
                } catch (Throwable t) {
                    Log.w(TAG, "cannot delete entry: " + file.filename, t);
                }
                return null;
            }
            synchronized (mEntryMap) {
                mEntryMap.put(downloadUrl, entry);
            }
            return entry;
        }
    }

    private FileEntry queryDatabase(String downloadUrl) {
        long hash = Utils.crc64Long(downloadUrl);
        String whereArgs[] = new String[] {String.valueOf(hash), downloadUrl};
        Cursor cursor = mDbHelper.getReadableDatabase().query(TABLE_NAME,
                FileEntry.SCHEMA.getProjection(),
                QUERY_WHERE, whereArgs, null, null, null);
        try {
            if (!cursor.moveToNext()) return null;
            FileEntry entry = new FileEntry();
            FileEntry.SCHEMA.cursorToObject(cursor, entry);
            updateLastAccess(entry.id);
            return entry;
        } finally {
            cursor.close();
        }
    }

    private void updateLastAccess(long id) {
        ContentValues values = new ContentValues();
        values.put(FileEntry.Columns.LAST_ACCESS, System.currentTimeMillis());
        mDbHelper.getWritableDatabase().update(TABLE_NAME,
                values,  ID_WHERE, new String[] {String.valueOf(id)});
    }

    public File createFile() throws IOException {
        return File.createTempFile(FILE_PREFIX, FILE_POSTFIX, mRootDir);
    }

    private synchronized void initialize() {
        if (mInitialized) return;

        if (!mRootDir.isDirectory()) {
            mRootDir.mkdirs();
            if (!mRootDir.isDirectory()) {
                throw new RuntimeException("cannot create: " + mRootDir.getAbsolutePath());
            }
        }

        Cursor cursor = mDbHelper.getReadableDatabase().query(
                TABLE_NAME, PROJECTION_SIZE_SUM,
                null, null, null, null, null);
        try {
            if (cursor.moveToNext()) mTotalBytes = cursor.getLong(0);
        } finally {
            cursor.close();
        }
        if (mTotalBytes > mCapacity) freeSomeSpaceIfNeed(MAX_DELETE_COUNT);

        // Mark initialized when everything above went through. If an exception was thrown,
        // initialize() will be retried later.
        mInitialized = true;
    }

    private void freeSomeSpaceIfNeed(int maxDeleteFileCount) {
        Cursor cursor = mDbHelper.getReadableDatabase().query(
                TABLE_NAME, FREESPACE_PROJECTION,
                null, null, null, null, FREESPACE_ORDER_BY);
        try {
            while (maxDeleteFileCount > 0
                    && mTotalBytes > mCapacity && cursor.moveToNext()) {
                long id = cursor.getLong(0);
                String path = cursor.getString(1);
                String url = cursor.getString(2);
                long size = cursor.getLong(3);

                synchronized (mEntryMap) {
                    // if some one still uses it
                    if (mEntryMap.containsKey(url)) continue;
                }

                --maxDeleteFileCount;
                if (new File(mRootDir, path).delete()) {
                    mTotalBytes -= size;
                    mDbHelper.getWritableDatabase().delete(TABLE_NAME,
                            ID_WHERE, new String[]{String.valueOf(id)});
                } else {
                    Log.w(TAG, "unable to delete file: " + path);
                }
            }
        } finally {
            cursor.close();
        }
    }

    @Table("files")
    private static class FileEntry extends Entry {
        public static final EntrySchema SCHEMA = new EntrySchema(FileEntry.class);

        public interface Columns extends Entry.Columns {
            public static final String HASH_CODE = "hash_code";
            public static final String CONTENT_URL = "content_url";
            public static final String FILENAME = "filename";
            public static final String SIZE = "size";
            public static final String LAST_ACCESS = "last_access";
        }

        @Column(value = Columns.HASH_CODE, indexed = true)
        public long hashCode;

        @Column(Columns.CONTENT_URL)
        public String contentUrl;

        @Column(Columns.FILENAME)
        public String filename;

        @Column(Columns.SIZE)
        public long size;

        @Column(value = Columns.LAST_ACCESS, indexed = true)
        public long lastAccess;

        @Override
        public String toString() {
            return new StringBuilder()
                    .append("hash_code: ").append(hashCode).append(", ")
                    .append("content_url").append(contentUrl).append(", ")
                    .append("last_access").append(lastAccess).append(", ")
                    .append("filename").append(filename).toString();
        }
    }

    private final class DatabaseHelper extends SQLiteOpenHelper {
        public static final int DATABASE_VERSION = 1;

        public DatabaseHelper(Context context, String dbName) {
            super(context, dbName, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            FileEntry.SCHEMA.createTables(db);

            // delete old files
            for (File file : mRootDir.listFiles()) {
                if (!file.delete()) {
                    Log.w(TAG, "fail to remove: " + file.getAbsolutePath());
                }
            }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            //reset everything
            FileEntry.SCHEMA.dropTables(db);
            onCreate(db);
        }
    }
}

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import com.android.gallery3d.common.Entry;
import com.android.gallery3d.common.EntrySchema;


@Entry.Table("download")
public class DownloadEntry extends Entry {
    public static final EntrySchema SCHEMA = new EntrySchema(DownloadEntry.class);

    public static interface Columns extends Entry.Columns {
        public static final String HASH_CODE = "hash_code";
        public static final String CONTENT_URL = "content_url";
        public static final String CONTENT_SIZE = "_size";
        public static final String ETAG = "etag";
        public static final String LAST_ACCESS = "last_access";
        public static final String LAST_UPDATED = "last_updated";
        public static final String DATA = "_data";
    }

    @Column(value = "hash_code", indexed = true)
    public long hashCode;

    @Column("content_url")
    public String contentUrl;

    @Column("_size")
    public long contentSize;

    @Column("etag")
    public String eTag;

    @Column(value = "last_access", indexed = true)
    public long lastAccessTime;

    @Column(value = "last_updated")
    public long lastUpdatedTime;

    @Column("_data")
    public String path;

    @Override
    public String toString() {
        // Note: THIS IS REQUIRED. We used all the fields here. Otherwise,
        //       ProGuard will remove these UNUSED fields. However, these
        //       fields are needed to generate database.
        return new StringBuilder()
                .append("hash_code: ").append(hashCode).append(", ")
                .append("content_url").append(contentUrl).append(", ")
                .append("_size").append(contentSize).append(", ")
                .append("etag").append(eTag).append(", ")
                .append("last_access").append(lastAccessTime).append(", ")
                .append("last_updated").append(lastUpdatedTime).append(",")
                .append("_data").append(path)
                .toString();
    }
}


/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import com.android.gallery3d.app.GalleryApp;
import com.android.gallery3d.common.LruCache;
import com.android.gallery3d.common.Utils;
import com.android.gallery3d.data.DownloadEntry.Columns;
import com.android.gallery3d.util.Future;
import com.android.gallery3d.util.FutureListener;
import com.android.gallery3d.util.ThreadPool;
import com.android.gallery3d.util.ThreadPool.CancelListener;
import com.android.gallery3d.util.ThreadPool.Job;
import com.android.gallery3d.util.ThreadPool.JobContext;

import java.io.File;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;

public class DownloadCache {
    private static final String TAG = "DownloadCache";
    private static final int MAX_DELETE_COUNT = 16;
    private static final int LRU_CAPACITY = 4;

    private static final String TABLE_NAME = DownloadEntry.SCHEMA.getTableName();

    private static final String QUERY_PROJECTION[] = {Columns.ID, Columns.DATA};
    private static final String WHERE_HASH_AND_URL = String.format(
            "%s = ? AND %s = ?", Columns.HASH_CODE, Columns.CONTENT_URL);
    private static final int QUERY_INDEX_ID = 0;
    private static final int QUERY_INDEX_DATA = 1;

    private static final String FREESPACE_PROJECTION[] = {
            Columns.ID, Columns.DATA, Columns.CONTENT_URL, Columns.CONTENT_SIZE};
    private static final String FREESPACE_ORDER_BY =
            String.format("%s ASC", Columns.LAST_ACCESS);
    private static final int FREESPACE_IDNEX_ID = 0;
    private static final int FREESPACE_IDNEX_DATA = 1;
    private static final int FREESPACE_INDEX_CONTENT_URL = 2;
    private static final int FREESPACE_INDEX_CONTENT_SIZE = 3;

    private static final String ID_WHERE = Columns.ID + " = ?";

    private static final String SUM_PROJECTION[] =
            {String.format("sum(%s)", Columns.CONTENT_SIZE)};
    private static final int SUM_INDEX_SUM = 0;

    private final LruCache<String, Entry> mEntryMap =
            new LruCache<String, Entry>(LRU_CAPACITY);
    private final HashMap<String, DownloadTask> mTaskMap =
            new HashMap<String, DownloadTask>();
    private final File mRoot;
    private final GalleryApp mApplication;
    private final SQLiteDatabase mDatabase;
    private final long mCapacity;

    private long mTotalBytes = 0;
    private boolean mInitialized = false;

    public DownloadCache(GalleryApp application, File root, long capacity) {
        mRoot = Utils.checkNotNull(root);
        mApplication = Utils.checkNotNull(application);
        mCapacity = capacity;
        mDatabase = new DatabaseHelper(application.getAndroidContext())
                .getWritableDatabase();
    }

    private Entry findEntryInDatabase(String stringUrl) {
        long hash = Utils.crc64Long(stringUrl);
        String whereArgs[] = {String.valueOf(hash), stringUrl};
        Cursor cursor = mDatabase.query(TABLE_NAME, QUERY_PROJECTION,
                WHERE_HASH_AND_URL, whereArgs, null, null, null);
        try {
            if (cursor.moveToNext()) {
                File file = new File(cursor.getString(QUERY_INDEX_DATA));
                long id = cursor.getInt(QUERY_INDEX_ID);
                Entry entry = null;
                synchronized (mEntryMap) {
                    entry = mEntryMap.get(stringUrl);
                    if (entry == null) {
                        entry = new Entry(id, file);
                        mEntryMap.put(stringUrl, entry);
                    }
                }
                return entry;
            }
        } finally {
            cursor.close();
        }
        return null;
    }

    public Entry download(JobContext jc, URL url) {
        if (!mInitialized) initialize();

        String stringUrl = url.toString();

        // First find in the entry-pool
        synchronized (mEntryMap) {
            Entry entry = mEntryMap.get(stringUrl);
            if (entry != null) {
                updateLastAccess(entry.mId);
                return entry;
            }
        }

        // Then, find it in database
        TaskProxy proxy = new TaskProxy();
        synchronized (mTaskMap) {
            Entry entry = findEntryInDatabase(stringUrl);
            if (entry != null) {
                updateLastAccess(entry.mId);
                return entry;
            }

            // Finally, we need to download the file ....
            // First check if we are downloading it now ...
            DownloadTask task = mTaskMap.get(stringUrl);
            if (task == null) { // if not, start the download task now
                task = new DownloadTask(stringUrl);
                mTaskMap.put(stringUrl, task);
                task.mFuture = mApplication.getThreadPool().submit(task, task);
            }
            task.addProxy(proxy);
        }

        return proxy.get(jc);
    }

    private void updateLastAccess(long id) {
        ContentValues values = new ContentValues();
        values.put(Columns.LAST_ACCESS, System.currentTimeMillis());
        mDatabase.update(TABLE_NAME, values,
                ID_WHERE, new String[] {String.valueOf(id)});
    }

    private synchronized void freeSomeSpaceIfNeed(int maxDeleteFileCount) {
        if (mTotalBytes <= mCapacity) return;
        Cursor cursor = mDatabase.query(TABLE_NAME,
                FREESPACE_PROJECTION, null, null, null, null, FREESPACE_ORDER_BY);
        try {
            while (maxDeleteFileCount > 0
                    && mTotalBytes > mCapacity && cursor.moveToNext()) {
                long id = cursor.getLong(FREESPACE_IDNEX_ID);
                String url = cursor.getString(FREESPACE_INDEX_CONTENT_URL);
                long size = cursor.getLong(FREESPACE_INDEX_CONTENT_SIZE);
                String path = cursor.getString(FREESPACE_IDNEX_DATA);
                boolean containsKey;
                synchronized (mEntryMap) {
                    containsKey = mEntryMap.containsKey(url);
                }
                if (!containsKey) {
                    --maxDeleteFileCount;
                    mTotalBytes -= size;
                    new File(path).delete();
                    mDatabase.delete(TABLE_NAME,
                            ID_WHERE, new String[]{String.valueOf(id)});
                } else {
                    // skip delete, since it is being used
                }
            }
        } finally {
            cursor.close();
        }
    }

    private synchronized long insertEntry(String url, File file) {
        long size = file.length();
        mTotalBytes += size;

        ContentValues values = new ContentValues();
        String hashCode = String.valueOf(Utils.crc64Long(url));
        values.put(Columns.DATA, file.getAbsolutePath());
        values.put(Columns.HASH_CODE, hashCode);
        values.put(Columns.CONTENT_URL, url);
        values.put(Columns.CONTENT_SIZE, size);
        values.put(Columns.LAST_UPDATED, System.currentTimeMillis());
        return mDatabase.insert(TABLE_NAME, "", values);
    }

    private synchronized void initialize() {
        if (mInitialized) return;
        mInitialized = true;
        if (!mRoot.isDirectory()) mRoot.mkdirs();
        if (!mRoot.isDirectory()) {
            throw new RuntimeException("cannot create " + mRoot.getAbsolutePath());
        }

        Cursor cursor = mDatabase.query(
                TABLE_NAME, SUM_PROJECTION, null, null, null, null, null);
        mTotalBytes = 0;
        try {
            if (cursor.moveToNext()) {
                mTotalBytes = cursor.getLong(SUM_INDEX_SUM);
            }
        } finally {
            cursor.close();
        }
        if (mTotalBytes > mCapacity) freeSomeSpaceIfNeed(MAX_DELETE_COUNT);
    }

    private final class DatabaseHelper extends SQLiteOpenHelper {
        public static final String DATABASE_NAME = "download.db";
        public static final int DATABASE_VERSION = 2;

        public DatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            DownloadEntry.SCHEMA.createTables(db);
            // Delete old files
            for (File file : mRoot.listFiles()) {
                if (!file.delete()) {
                    Log.w(TAG, "fail to remove: " + file.getAbsolutePath());
                }
            }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            //reset everything
            DownloadEntry.SCHEMA.dropTables(db);
            onCreate(db);
        }
    }

    public class Entry {
        public File cacheFile;
        protected long mId;

        Entry(long id, File cacheFile) {
            mId = id;
            this.cacheFile = Utils.checkNotNull(cacheFile);
        }
    }

    private class DownloadTask implements Job<File>, FutureListener<File> {
        private HashSet<TaskProxy> mProxySet = new HashSet<TaskProxy>();
        private Future<File> mFuture;
        private final String mUrl;

        public DownloadTask(String url) {
            mUrl = Utils.checkNotNull(url);
        }

        public void removeProxy(TaskProxy proxy) {
            synchronized (mTaskMap) {
                Utils.assertTrue(mProxySet.remove(proxy));
                if (mProxySet.isEmpty()) {
                    mFuture.cancel();
                    mTaskMap.remove(mUrl);
                }
            }
        }

        // should be used in synchronized block of mDatabase
        public void addProxy(TaskProxy proxy) {
            proxy.mTask = this;
            mProxySet.add(proxy);
        }

        @Override
        public void onFutureDone(Future<File> future) {
            File file = future.get();
            long id = 0;
            if (file != null) { // insert to database
                id = insertEntry(mUrl, file);
            }

            if (future.isCancelled()) {
                Utils.assertTrue(mProxySet.isEmpty());
                return;
            }

            synchronized (mTaskMap) {
                Entry entry = null;
                synchronized (mEntryMap) {
                    if (file != null) {
                        entry = new Entry(id, file);
                        Utils.assertTrue(mEntryMap.put(mUrl, entry) == null);
                    }
                }
                for (TaskProxy proxy : mProxySet) {
                    proxy.setResult(entry);
                }
                mTaskMap.remove(mUrl);
                freeSomeSpaceIfNeed(MAX_DELETE_COUNT);
            }
        }

        @Override
        public File run(JobContext jc) {
            // TODO: utilize etag
            jc.setMode(ThreadPool.MODE_NETWORK);
            File tempFile = null;
            try {
                URL url = new URL(mUrl);
                tempFile = File.createTempFile("cache", ".tmp", mRoot);
                // download from url to tempFile
                jc.setMode(ThreadPool.MODE_NETWORK);
                boolean downloaded = DownloadUtils.requestDownload(jc, url, tempFile);
                jc.setMode(ThreadPool.MODE_NONE);
                if (downloaded) return tempFile;
            } catch (Exception e) {
                Log.e(TAG, String.format("fail to download %s", mUrl), e);
            } finally {
                jc.setMode(ThreadPool.MODE_NONE);
            }
            if (tempFile != null) tempFile.delete();
            return null;
        }
    }

    public static class TaskProxy {
        private DownloadTask mTask;
        private boolean mIsCancelled = false;
        private Entry mEntry;

        synchronized void setResult(Entry entry) {
            if (mIsCancelled) return;
            mEntry = entry;
            notifyAll();
        }

        public synchronized Entry get(JobContext jc) {
            jc.setCancelListener(new CancelListener() {
                @Override
                public void onCancel() {
                    mTask.removeProxy(TaskProxy.this);
                    synchronized (TaskProxy.this) {
                        mIsCancelled = true;
                        TaskProxy.this.notifyAll();
                    }
                }
            });
            while (!mIsCancelled && mEntry == null) {
                try {
                    wait();
                } catch (InterruptedException e) {
                    Log.w(TAG, "ignore interrupt", e);
                }
            }
            jc.setCancelListener(null);
            return mEntry;
        }
    }
}

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import com.android.gallery3d.common.Utils;
import com.android.gallery3d.util.ThreadPool.CancelListener;
import com.android.gallery3d.util.ThreadPool.JobContext;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.net.URL;

public class DownloadUtils {
    private static final String TAG = "DownloadService";

    public static boolean requestDownload(JobContext jc, URL url, File file) {
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            return download(jc, url, fos);
        } catch (Throwable t) {
            return false;
        } finally {
            Utils.closeSilently(fos);
        }
    }

    public static void dump(JobContext jc, InputStream is, OutputStream os)
            throws IOException {
        byte buffer[] = new byte[4096];
        int rc = is.read(buffer, 0, buffer.length);
        final Thread thread = Thread.currentThread();
        jc.setCancelListener(new CancelListener() {
            @Override
            public void onCancel() {
                thread.interrupt();
            }
        });
        while (rc > 0) {
            if (jc.isCancelled()) throw new InterruptedIOException();
            os.write(buffer, 0, rc);
            rc = is.read(buffer, 0, buffer.length);
        }
        jc.setCancelListener(null);
        Thread.interrupted(); // consume the interrupt signal
    }

    public static boolean download(JobContext jc, URL url, OutputStream output) {
        InputStream input = null;
        try {
            input = url.openStream();
            dump(jc, input, output);
            return true;
        } catch (Throwable t) {
            Log.w(TAG, "fail to download", t);
            return false;
        } finally {
            Utils.closeSilently(input);
        }
    }
}

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import android.annotation.TargetApi;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.BitmapRegionDecoder;
import android.os.Build;
import android.util.FloatMath;

import com.android.gallery3d.common.ApiHelper;
import com.android.gallery3d.common.BitmapUtils;
import com.android.gallery3d.common.Utils;
import com.android.gallery3d.ui.Log;
import com.android.gallery3d.util.ThreadPool.CancelListener;
import com.android.gallery3d.util.ThreadPool.JobContext;

import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.InputStream;

public class DecodeUtils {
    private static final String TAG = "DecodeUtils";

    private static class DecodeCanceller implements CancelListener {
        Options mOptions;

        public DecodeCanceller(Options options) {
            mOptions = options;
        }

        @Override
        public void onCancel() {
            mOptions.requestCancelDecode();
        }
    }

    @TargetApi(ApiHelper.VERSION_CODES.HONEYCOMB)
    public static void setOptionsMutable(Options options) {
        if (ApiHelper.HAS_OPTIONS_IN_MUTABLE) options.inMutable = true;
    }

    public static Bitmap decode(JobContext jc, FileDescriptor fd, Options options) {
        if (options == null) options = new Options();
        jc.setCancelListener(new DecodeCanceller(options));
        setOptionsMutable(options);
        return ensureGLCompatibleBitmap(
                BitmapFactory.decodeFileDescriptor(fd, null, options));
    }

    public static void decodeBounds(JobContext jc, FileDescriptor fd,
            Options options) {
        Utils.assertTrue(options != null);
        options.inJustDecodeBounds = true;
        jc.setCancelListener(new DecodeCanceller(options));
        BitmapFactory.decodeFileDescriptor(fd, null, options);
        options.inJustDecodeBounds = false;
    }

    public static Bitmap decode(JobContext jc, byte[] bytes, Options options) {
        return decode(jc, bytes, 0, bytes.length, options);
    }

    public static Bitmap decode(JobContext jc, byte[] bytes, int offset,
            int length, Options options) {
        if (options == null) options = new Options();
        jc.setCancelListener(new DecodeCanceller(options));
        setOptionsMutable(options);
        return ensureGLCompatibleBitmap(
                BitmapFactory.decodeByteArray(bytes, offset, length, options));
    }

    public static void decodeBounds(JobContext jc, byte[] bytes, int offset,
            int length, Options options) {
        Utils.assertTrue(options != null);
        options.inJustDecodeBounds = true;
        jc.setCancelListener(new DecodeCanceller(options));
        BitmapFactory.decodeByteArray(bytes, offset, length, options);
        options.inJustDecodeBounds = false;
    }

    public static Bitmap decodeThumbnail(
            JobContext jc, String filePath, Options options, int targetSize, int type) {
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(filePath);
            FileDescriptor fd = fis.getFD();
            return decodeThumbnail(jc, fd, options, targetSize, type);
        } catch (Exception ex) {
            Log.w(TAG, ex);
            return null;
        } finally {
            Utils.closeSilently(fis);
        }
    }

    public static Bitmap decodeThumbnail(
            JobContext jc, FileDescriptor fd, Options options, int targetSize, int type) {
        if (options == null) options = new Options();
        jc.setCancelListener(new DecodeCanceller(options));

        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFileDescriptor(fd, null, options);
        if (jc.isCancelled()) return null;

        int w = options.outWidth;
        int h = options.outHeight;

        if (type == MediaItem.TYPE_MICROTHUMBNAIL) {
            // We center-crop the original image as it's micro thumbnail. In this case,
            // we want to make sure the shorter side >= "targetSize".
            float scale = (float) targetSize / Math.min(w, h);
            options.inSampleSize = BitmapUtils.computeSampleSizeLarger(scale);

            // For an extremely wide image, e.g. 300x30000, we may got OOM when decoding
            // it for TYPE_MICROTHUMBNAIL. So we add a max number of pixels limit here.
            final int MAX_PIXEL_COUNT = 640000; // 400 x 1600
            if ((w / options.inSampleSize) * (h / options.inSampleSize) > MAX_PIXEL_COUNT) {
                options.inSampleSize = BitmapUtils.computeSampleSize(
                        FloatMath.sqrt((float) MAX_PIXEL_COUNT / (w * h)));
            }
        } else {
            // For screen nail, we only want to keep the longer side >= targetSize.
            float scale = (float) targetSize / Math.max(w, h);
            options.inSampleSize = BitmapUtils.computeSampleSizeLarger(scale);
        }

        options.inJustDecodeBounds = false;
        setOptionsMutable(options);

        Bitmap result = BitmapFactory.decodeFileDescriptor(fd, null, options);
        if (result == null) return null;

        // We need to resize down if the decoder does not support inSampleSize
        // (For example, GIF images)
        float scale = (float) targetSize / (type == MediaItem.TYPE_MICROTHUMBNAIL
                ? Math.min(result.getWidth(), result.getHeight())
                : Math.max(result.getWidth(), result.getHeight()));

        if (scale <= 0.5) result = BitmapUtils.resizeBitmapByScale(result, scale, true);
        return ensureGLCompatibleBitmap(result);
    }

    /**
     * Decodes the bitmap from the given byte array if the image size is larger than the given
     * requirement.
     *
     * Note: The returned image may be resized down. However, both width and height must be
     * larger than the <code>targetSize</code>.
     */
    public static Bitmap decodeIfBigEnough(JobContext jc, byte[] data,
            Options options, int targetSize) {
        if (options == null) options = new Options();
        jc.setCancelListener(new DecodeCanceller(options));

        options.inJustDecodeBounds = true;
        BitmapFactory.decodeByteArray(data, 0, data.length, options);
        if (jc.isCancelled()) return null;
        if (options.outWidth < targetSize || options.outHeight < targetSize) {
            return null;
        }
        options.inSampleSize = BitmapUtils.computeSampleSizeLarger(
                options.outWidth, options.outHeight, targetSize);
        options.inJustDecodeBounds = false;
        setOptionsMutable(options);

        return ensureGLCompatibleBitmap(
                BitmapFactory.decodeByteArray(data, 0, data.length, options));
    }

    // TODO: This function should not be called directly from
    // DecodeUtils.requestDecode(...), since we don't have the knowledge
    // if the bitmap will be uploaded to GL.
    public static Bitmap ensureGLCompatibleBitmap(Bitmap bitmap) {
        if (bitmap == null || bitmap.getConfig() != null) return bitmap;
        Bitmap newBitmap = bitmap.copy(Config.ARGB_8888, false);
        bitmap.recycle();
        return newBitmap;
    }

    public static BitmapRegionDecoder createBitmapRegionDecoder(
            JobContext jc, byte[] bytes, int offset, int length,
            boolean shareable) {
        if (offset < 0 || length <= 0 || offset + length > bytes.length) {
            throw new IllegalArgumentException(String.format(
                    "offset = %s, length = %s, bytes = %s",
                    offset, length, bytes.length));
        }

        try {
            return BitmapRegionDecoder.newInstance(
                    bytes, offset, length, shareable);
        } catch (Throwable t)  {
            Log.w(TAG, t);
            return null;
        }
    }

    public static BitmapRegionDecoder createBitmapRegionDecoder(
            JobContext jc, String filePath, boolean shareable) {
        try {
            return BitmapRegionDecoder.newInstance(filePath, shareable);
        } catch (Throwable t)  {
            Log.w(TAG, t);
            return null;
        }
    }

    public static BitmapRegionDecoder createBitmapRegionDecoder(
            JobContext jc, FileDescriptor fd, boolean shareable) {
        try {
            return BitmapRegionDecoder.newInstance(fd, shareable);
        } catch (Throwable t)  {
            Log.w(TAG, t);
            return null;
        }
    }

    public static BitmapRegionDecoder createBitmapRegionDecoder(
            JobContext jc, InputStream is, boolean shareable) {
        try {
            return BitmapRegionDecoder.newInstance(is, shareable);
        } catch (Throwable t)  {
            // We often cancel the creating of bitmap region decoder,
            // so just log one line.
            Log.w(TAG, "requestCreateBitmapRegionDecoder: " + t);
            return null;
        }
    }

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public static Bitmap decode(JobContext jc, byte[] data, int offset,
            int length, BitmapFactory.Options options, BitmapPool pool) {
        if (pool == null) {
            return decode(jc, data, offset, length, options);
        }

        if (options == null) options = new BitmapFactory.Options();
        if (options.inSampleSize < 1) options.inSampleSize = 1;
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        options.inBitmap = (options.inSampleSize == 1)
                ? findCachedBitmap(pool, jc, data, offset, length, options) : null;
        try {
            Bitmap bitmap = decode(jc, data, offset, length, options);
            if (options.inBitmap != null && options.inBitmap != bitmap) {
                pool.recycle(options.inBitmap);
                options.inBitmap = null;
            }
            return bitmap;
        } catch (IllegalArgumentException e) {
            if (options.inBitmap == null) throw e;

            Log.w(TAG, "decode fail with a given bitmap, try decode to a new bitmap");
            pool.recycle(options.inBitmap);
            options.inBitmap = null;
            return decode(jc, data, offset, length, options);
        }
    }

    // This is the same as the method above except the source data comes
    // from a file descriptor instead of a byte array.
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public static Bitmap decode(JobContext jc,
            FileDescriptor fileDescriptor, Options options, BitmapPool pool) {
        if (pool == null) {
            return decode(jc, fileDescriptor, options);
        }

        if (options == null) options = new BitmapFactory.Options();
        if (options.inSampleSize < 1) options.inSampleSize = 1;
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        options.inBitmap = (options.inSampleSize == 1)
                ? findCachedBitmap(pool, jc, fileDescriptor, options) : null;
        try {
            Bitmap bitmap = DecodeUtils.decode(jc, fileDescriptor, options);
            if (options.inBitmap != null && options.inBitmap != bitmap) {
                pool.recycle(options.inBitmap);
                options.inBitmap = null;
            }
            return bitmap;
        } catch (IllegalArgumentException e) {
            if (options.inBitmap == null) throw e;

            Log.w(TAG, "decode fail with a given bitmap, try decode to a new bitmap");
            pool.recycle(options.inBitmap);
            options.inBitmap = null;
            return decode(jc, fileDescriptor, options);
        }
    }

    private static Bitmap findCachedBitmap(BitmapPool pool, JobContext jc,
            byte[] data, int offset, int length, Options options) {
        if (pool.isOneSize()) return pool.getBitmap();
        decodeBounds(jc, data, offset, length, options);
        return pool.getBitmap(options.outWidth, options.outHeight);
    }

    private static Bitmap findCachedBitmap(BitmapPool pool, JobContext jc,
            FileDescriptor fileDescriptor, Options options) {
        if (pool.isOneSize()) return pool.getBitmap();
        decodeBounds(jc, fileDescriptor, options);
        return pool.getBitmap(options.outWidth, options.outHeight);
    }
}