add ability to save segments of the file (#800)

src/dataEditor/dataEditorClient.ts

@@ -18,14 +18,17 @@
 import fs from 'fs'
 import {
   ALL_EVENTS,
+  beginSessionTransaction,
   clear,
   CountKind,
   createSession,
   createSimpleFileLogger,
   createViewport,
+  del,
   destroySession,
   edit,
   EditorClient,
+  endSessionTransaction,
   EventSubscriptionRequest,
   getClient,
   getClientVersion,
@@ -489,6 +492,22 @@ export class DataEditorClient implements vscode.Disposable {
         }
         break
 
+      case MessageCommand.saveSegment:
+        {
+          const uri = await vscode.window.showSaveDialog({
+            title: 'Save Segment',
+            saveLabel: 'Save',
+          })
+          if (uri && uri.fsPath) {
+            await this.saveFileSegment(
+              uri.fsPath,
+              message.data.offset,
+              message.data.length
+            )
+          }
+        }
+        break
+
       case MessageCommand.requestEditedData:
         {
           const [selectionData, selectionDisplay] = fillRequestData(message)
@@ -578,6 +597,87 @@ export class DataEditorClient implements vscode.Disposable {
     }
   }
 
+  private async saveFileSegment(
+    fileToSave: string,
+    offset: number,
+    length: number
+  ) {
+    // if the file to save is the same as the file being edited then we can save the file with a single transaction to
+    // trim the file to contain only the desired segment, preserving session state
+    if (this.fileToEdit === fileToSave) {
+      const computedFileSize = await getComputedFileSize(this.omegaSessionId)
+      if (offset === 0) {
+        if (offset + length !== computedFileSize) {
+          // delete from length to the end of the file
+          await del(this.omegaSessionId, length, computedFileSize - length)
+          await this.sendChangesInfo()
+        }
+      } else if (offset + length === computedFileSize) {
+        // delete from 0 to offset
+        await del(this.omegaSessionId, 0, offset)
+        await this.sendChangesInfo()
+      } else {
+        // delete from length to the end of the file and from 0 to offset in a single transaction
+        await beginSessionTransaction(this.omegaSessionId)
+        await del(
+          this.omegaSessionId,
+          offset + length,
+          computedFileSize - length
+        )
+        await del(this.omegaSessionId, 0, offset)
+        await endSessionTransaction(this.omegaSessionId)
+        await this.sendChangesInfo()
+      }
+      // save the segment to the file using the typical save method
+      await this.saveFile(fileToSave)
+    } else {
+      let saved = false
+      let cancelled = false
+
+      // try to save the file with overwrite
+      const saveResponse = await saveSession(
+        this.omegaSessionId,
+        fileToSave,
+        IOFlags.IO_FLG_OVERWRITE,
+        offset,
+        length
+      )
+      if (saveResponse.getSaveStatus() === SaveStatus.MODIFIED) {
+        // the file was modified since the session was created, query user to overwrite the modified file
+        if (
+          (await vscode.window.showInformationMessage(
+            'File has been modified since being opened overwrite the file anyway?',
+            { modal: true },
+            'Yes',
+            'No'
+          )) === 'Yes'
+        ) {
+          // the user decided to overwrite the file, try to save again with force overwrite
+          const saveResponse2 = await saveSession(
+            this.omegaSessionId,
+            fileToSave,
+            IOFlags.IO_FLG_FORCE_OVERWRITE,
+            offset,
+            length
+          )
+          saved = saveResponse2.getSaveStatus() === SaveStatus.SUCCESS
+        } else {
+          cancelled = true
+        }
+      } else {
+        saved = saveResponse.getSaveStatus() === SaveStatus.SUCCESS
+      }
+
+      if (saved) {
+        vscode.window.showInformationMessage(`Saved: ${this.fileToEdit}`)
+      } else if (cancelled) {
+        vscode.window.showInformationMessage(`Cancelled save: ${fileToSave}`)
+      } else {
+        vscode.window.showErrorMessage(`Failed to save: ${fileToSave}`)
+      }
+    }
+  }
+
   private async saveFile(fileToSave: string) {
     let saved = false
     let cancelled = false

src/svelte/src/components/DataMetrics/DataMetrics.svelte

@@ -129,6 +129,16 @@ limitations under the License.
     link.click()
   }
 
+  function saveSegmentAs() {
+    vscode.postMessage({
+      command: MessageCommand.saveSegment,
+        data: {
+            offset: startOffset,
+            length: length,
+        },
+    })
+  }
+
   function requestSessionProfile(startOffset: number, length: number) {
     setStatusMessage(
       `Profiling bytes from ${startOffset} to ${startOffset + length}...`,
@@ -493,13 +503,13 @@ limitations under the License.
     </label>
   </div>
   <hr />
-  <Button
-    fn={handleCsvProfileDownload}
-    description="Download profiled data as .csv"
-  >
+  <Button fn={handleCsvProfileDownload} description="Download profiled data as .csv">
     <span slot="left" class="btn-icon material-symbols-outlined">download</span>
-    <span>Profile&nbsp;as&nbsp;CSV</span></Button
-  >
+    <span>Profile&nbsp;as&nbsp;CSV</span></Button>
+  <Button fn={saveSegmentAs} description="Save segment as">
+    <span slot="left" class="btn-icon material-symbols-outlined">save_as</span>
+    <span slot="default">Save&nbsp;Segment&nbsp;As</span>
+  </Button>
   <hr />
   {#if statusMessage.length > 0}
     <div class="message status">&nbsp;{statusMessage}&nbsp;</div>

src/svelte/src/components/Header/fieldsets/FileMetrics.svelte

@@ -65,6 +65,9 @@ limitations under the License.
     switch (msg.data.command) {
       case MessageCommand.fileInfo:
         {
+          // reset the profiler if changes have been made
+          isProfilerOpen = false
+          startOffset = length = 0
           if ('fileName' in msg.data.data) {
             $fileMetrics.name = msg.data.data.fileName
           }

src/svelte/src/utilities/message.ts

@@ -27,6 +27,7 @@ export enum MessageCommand {
   requestEditedData,
   save,
   saveAs,
+  saveSegment,
   scrollViewport,
   search,
   replace,

yarn.lock

@@ -412,7 +412,7 @@
     jszip "^3.10.1"
     semver "^7.5.2"
 
-"@vscode/[email protected]", "@vscode/vsce@^2.20.1":
+"@vscode/[email protected]":
   version "2.22.0"
   resolved "https://registry.yarnpkg.com/@vscode/vsce/-/vsce-2.22.0.tgz#1eb3ebc6b89581a150bb44dd7d731a064019b617"
   integrity sha512-8df4uJiM3C6GZ2Sx/KilSKVxsetrTBBIUb3c0W4B1EWHcddioVs5mkyDKtMNP0khP/xBILVSzlXxhV+nm2rC9A==
@@ -440,6 +440,34 @@
   optionalDependencies:
     keytar "^7.7.0"
 
+"@vscode/vsce@^2.20.1":
+  version "2.21.0"
+  resolved "https://registry.yarnpkg.com/@vscode/vsce/-/vsce-2.21.0.tgz#572e66db79cff383b9ac39f71710aa62e6392330"
+  integrity sha512-KuxYqScqUY/duJbkj9eE2tN2X/WJoGAy54hHtxT3ZBkM6IzrOg7H7CXGUPBxNlmqku2w/cAjOUSrgIHlzz0mbA==
+  dependencies:
+    azure-devops-node-api "^11.0.1"
+    chalk "^2.4.2"
+    cheerio "^1.0.0-rc.9"
+    commander "^6.2.1"
+    glob "^7.0.6"
+    hosted-git-info "^4.0.2"
+    jsonc-parser "^3.2.0"
+    leven "^3.1.0"
+    markdown-it "^12.3.2"
+    mime "^1.3.4"
+    minimatch "^3.0.3"
+    parse-semver "^1.1.1"
+    read "^1.0.7"
+    semver "^7.5.2"
+    tmp "^0.2.1"
+    typed-rest-client "^1.8.4"
+    url-join "^4.0.1"
+    xml2js "^0.5.0"
+    yauzl "^2.3.1"
+    yazl "^2.2.2"
+  optionalDependencies:
+    keytar "^7.7.0"
+
 "@webassemblyjs/[email protected]", "@webassemblyjs/ast@^1.11.5":
   version "1.11.6"
   resolved "https://registry.yarnpkg.com/@webassemblyjs/ast/-/ast-1.11.6.tgz#db046555d3c413f8966ca50a95176a0e2c642e24"