db: store ints as ints, not floats

DatabaseULog.write_ulog complained about wrong value types during struct
packing.

pyulog/db.py

@@ -49,7 +49,7 @@ class DatabaseULog(ULog):
     contsructor will throw an exception. See the documentation of
     "ulog_migratedb" for more information.
     '''
-    SCHEMA_VERSION = 3
+    SCHEMA_VERSION = 4
 
     @staticmethod
     def get_db_handle(db_path):

pyulog/sql/pyulog.4.sql

@@ -0,0 +1,67 @@
+BEGIN;
+PRAGMA foreign_keys=off;
+
+-- Change REAL timestamps to INT. SQLITE only supports INT64, but ULog
+-- timestamps are UINT64. We accept losing 1 bit at the top end, since 2^63
+-- microseconds = 400,000 years. which should be enough.
+
+CREATE TABLE IF NOT EXISTS ULog_tmp (
+        Id INTEGER PRIMARY KEY AUTOINCREMENT,
+        SHA256Sum TEXT UNIQUE,
+        FileVersion INT,
+        StartTimestamp INT, -- changed from REAL
+        LastTimestamp INT, -- changed from REAL
+        CompatFlags TEXT,
+        IncompatFlags TEXT,
+        SyncCount INT,
+        HasSync BOOLEAN
+);
+INSERT OR IGNORE INTO ULog_tmp (Id, SHA256Sum, FileVersion, StartTimestamp, LastTimestamp, CompatFlags, IncompatFlags, SyncCount, HasSync) SELECT Id, SHA256Sum, FileVersion, StartTimestamp, LastTimestamp, CompatFlags, IncompatFlags, SyncCount, HasSync FROM ULog;
+
+CREATE TABLE IF NOT EXISTS ULogMessageDropout_tmp (
+        Timestamp INT, -- changed from REAL
+        Duration INT, -- changed from FLOAT
+        ULogId INT REFERENCES ULog (Id) ON DELETE CASCADE
+);
+INSERT OR IGNORE INTO ULogMessageDropout_tmp SELECT * FROM ULogMessageDropout;
+
+CREATE TABLE IF NOT EXISTS ULogMessageLogging_tmp (
+        LogLevel INT,
+        Timestamp INT,
+        Message TEXT,
+        ULogId INT REFERENCES ULog (Id) ON DELETE CASCADE
+);
+INSERT OR IGNORE INTO ULogMessageLogging_tmp SELECT * FROM ULogMessageLogging;
+
+CREATE TABLE IF NOT EXISTS ULogMessageLoggingTagged_tmp (
+        LogLevel INT,
+        Timestamp INT, -- changed from REAL
+        Tag INT,
+        Message TEXT,
+        ULogId INT REFERENCES ULog (Id) ON DELETE CASCADE
+);
+INSERT OR IGNORE INTO ULogMessageLoggingTagged_tmp SELECT * FROM ULogMessageLoggingTagged;
+
+CREATE TABLE IF NOT EXISTS ULogChangedParameter_tmp (
+        Timestamp INT, -- changed from REAL
+        Key TEXT,
+        Value BLOB,
+        ULogId INT REFERENCES ULog (Id) ON DELETE CASCADE
+);
+INSERT OR IGNORE INTO ULogChangedParameter_tmp SELECT * FROM ULogChangedParameter;
+
+
+DROP TABLE ULog;
+DROP TABLE ULogMessageDropout;
+DROP TABLE ULogMessageLogging;
+DROP TABLE ULogMessageLoggingTagged;
+DROP TABLE ULogChangedParameter;
+
+ALTER TABLE ULog_tmp RENAME TO ULog;
+ALTER TABLE ULogMessageDropout_tmp RENAME TO ULogMessageDropout;
+ALTER TABLE ULogMessageLogging_tmp RENAME TO ULogMessageLogging;
+ALTER TABLE ULogMessageLoggingTagged_tmp RENAME TO ULogMessageLoggingTagged;
+ALTER TABLE ULogChangedParameter_tmp RENAME TO ULogChangedParameter;
+
+PRAGMA foreign_keys=on;
+COMMIT;