Merge pull request #152 from dyedgreen/149-use-unstable-locking-api

Add file locking to deno VFS
dyedgreen · Nov 11, 2021 · b33cbd1 · b33cbd1
2 parents f366245 + d9fbf4f
commit b33cbd1
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Showing 8 changed files with 52 additions and 11 deletions.
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
@@ -33,5 +33,7 @@ jobs:
         make clean
     - name: Run tests
       run: /home/runner/.deno/bin/deno test --allow-read --allow-write test.ts
+    - name: Run tests (unstable)
+      run: /home/runner/.deno/bin/deno test --unstable --allow-read --allow-write test.ts
     - name: Run benchmarks
       run: /home/runner/.deno/bin/deno run bench.ts
diff --git a/build/size.txt b/build/size.txt
@@ -1,7 +1,7 @@
 sqlite.d.ts    ➜   2058 bytes
-sqlite.js      ➜ 894808 bytes
-sqlite.js.br   ➜ 299743 bytes
-sqlite.js.gz   ➜ 364032 bytes
-sqlite.wasm    ➜ 670595 bytes
-sqlite.wasm.br ➜ 237161 bytes
-sqlite.wasm.gz ➜ 278362 bytes
+sqlite.js      ➜ 894972 bytes
+sqlite.js.br   ➜ 300076 bytes
+sqlite.js.gz   ➜ 364271 bytes
+sqlite.wasm    ➜ 670718 bytes
+sqlite.wasm.br ➜ 237016 bytes
+sqlite.wasm.gz ➜ 278993 bytes
diff --git a/build/sqlite.js b/build/sqlite.js
diff --git a/build/sqlite.wasm b/build/sqlite.wasm
diff --git a/build/src/imports.h b/build/src/imports.h
@@ -12,6 +12,8 @@ extern int    js_write(int, const char*, double, int);
 extern void   js_truncate(int, double);
 extern void   js_sync(int);
 extern double js_size(int);
+extern void   js_lock(int, int);
+extern void   js_unlock(int);
 extern double js_time();
 extern int    js_timezone();
 extern int    js_exists(const char*);

diff --git a/build/src/vfs.c b/build/src/vfs.c
@@ -101,17 +101,42 @@ static int denoFileSize(sqlite3_file *pFile, sqlite_int64 *pSize) {
   return SQLITE_OK;
 }
 
-// Deno does not support file locks.
+// File locking
 static int denoLock(sqlite3_file *pFile, int eLock) {
-  debug_printf("no-op call to lock");
+  DenoFile *p = (DenoFile*)pFile;
+  switch (eLock) {
+    case SQLITE_LOCK_NONE:
+      // no op
+      break;
+    case SQLITE_LOCK_SHARED:
+    case SQLITE_LOCK_RESERVED: // one WASM process <-> one open database
+      js_lock(p->rid, 0);
+      break;
+    case SQLITE_LOCK_PENDING:
+    case SQLITE_LOCK_EXCLUSIVE:
+      js_lock(p->rid, 1);
+      break;
+  }
   return SQLITE_OK;
 }
+
 static int denoUnlock(sqlite3_file *pFile, int eLock) {
-  debug_printf("no-op call to unlock");
+    DenoFile *p = (DenoFile*)pFile;
+  switch (eLock) {
+    case SQLITE_LOCK_NONE:
+      // no op
+      break;
+    case SQLITE_LOCK_SHARED:
+    case SQLITE_LOCK_RESERVED:
+    case SQLITE_LOCK_PENDING:
+    case SQLITE_LOCK_EXCLUSIVE:
+      js_unlock(p->rid);
+      break;
+  }
   return SQLITE_OK;
 }
+
 static int denoCheckReservedLock(sqlite3_file *pFile, int *pResOut) {
-  debug_printf("no-op call to check reserved lock");
   *pResOut = 0;
   return SQLITE_OK;
 }

diff --git a/build/vfs.js b/build/vfs.js
@@ -68,6 +68,16 @@ export default function env(inst) {
     js_size: (rid) => {
       return Deno.fstatSync(rid).size;
     },
+    // Acquire a SHARED or EXCLUSIVE file lock
+    js_lock: (rid, exclusive) => {
+      // this is unstable ...
+      if (Deno.flockSync) Deno.flockSync(rid, exclusive !== 0);
+    },
+    // Release a file lock
+    js_unlock: (rid) => {
+      // this is unstable ...
+      if (Deno.funlockSync) Deno.funlockSync(rid);
+    },
     // Return current time in ms since UNIX epoch
     js_time: () => {
       return Date.now();

diff --git a/build/vfs.syms b/build/vfs.syms
@@ -7,6 +7,8 @@ js_write
 js_truncate
 js_sync
 js_size
+js_lock
+js_unlock
 js_time
 js_timezone
 js_exists