sqlite go vfs work of dubious correctness: open, close

Change-Id: I1bf4e67a3f96a53285635f0816075790a4543b55

misc/sqlite/sqlite3_os_go.c

@@ -6,23 +6,34 @@
 #define SKIP_SQLITE_VERSION
 #include "sqlite3.h"
 
+static sqlite3_io_methods g_file_methods;
+
 typedef struct GoFile GoFile;
 struct GoFile {
   sqlite3_io_methods const *pMethod;  /* Always the first entry */
+  int fd;
 };
 
+static int go_file_close(sqlite3_file* file) {
+  return GoFileClose(((GoFile*) file)->fd) == 0 ? SQLITE_OK : SQLITE_ERROR;
+}
+
 static int go_vfs_open(sqlite3_vfs* vfs,
                        const char* zName,
                        sqlite3_file* file,
                        int flags,
                        int* pOutFlags) {
-  struct GoVFSOpen_return r;
-  r = GoVFSOpen((char*) zName, flags);
-  if (r.r0 == -1) {
+  GoFile* go_file = (GoFile*) file;
+  memset(go_file, 0, sizeof(go_file));
+
+  const int fd = GoVFSOpen((char*) zName, flags);
+  if (fd == -1) {
     return SQLITE_ERROR;
   }
 
-  return SQLITE_ERROR;
+  go_file->pMethod = &g_file_methods;
+  go_file->fd = fd;
+  return SQLITE_OK;
 }
 
 int sqlite3_os_init(void) {
@@ -36,8 +47,6 @@ int sqlite3_os_init(void) {
   vfs.pAppData = NULL;
   vfs.xOpen = go_vfs_open;
 #if 0
-  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
-               int flags, int *pOutFlags);
   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
@@ -69,6 +78,31 @@ int sqlite3_os_init(void) {
 };
 #endif
   sqlite3_vfs_register(&vfs, 1);
+
+  memset(&g_file_methods, 0, sizeof(g_file_methods));
+  g_file_methods.iVersion = 1;
+  g_file_methods.xClose = go_file_close;
+#if 0
+  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
+  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
+  int (*xSync)(sqlite3_file*, int flags);
+  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
+  int (*xLock)(sqlite3_file*, int);
+  int (*xUnlock)(sqlite3_file*, int);
+  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
+  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
+  int (*xSectorSize)(sqlite3_file*);
+  int (*xDeviceCharacteristics)(sqlite3_file*);
+  /* Methods above are valid for version 1 */
+  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
+  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
+  void (*xShmBarrier)(sqlite3_file*);
+  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
+  /* Methods above are valid for version 2 */
+  /* Additional methods may be added in future releases */
+#endif
+
   return SQLITE_OK;
 }
 

misc/sqlite/vfs.go

@@ -1,9 +1,38 @@
 package sqlite
 
 import "C"
+import "os"
+import "sync"
+
+var file_map_mutex sync.Mutex
+var file_map = make(map[int]*os.File)
+
+func GetFile(fd int) (file *os.File) {
+	file_map_mutex.Lock()
+	defer file_map_mutex.Unlock()
+	return file_map[fd]
+}
+
+//export GoFileClose
+// Returns 0 on success and 1 on error.
+func GoFileClose(fd C.int) (int) {
+	file := GetFile(int(fd))
+	if file.Close() != nil {
+		return 1
+	}
+	return 0
+}
 
 //export GoVFSOpen
 // fd is -1 on error.
-func GoVFSOpen(filename *C.char, flags C.int) (int, int) {
-	return -1, 0
+func GoVFSOpen(filename *C.char, flags C.int) (int) {
+	file, err := os.OpenFile(C.GoString(filename), int(flags), 0)
+	if err != nil {
+		return -1
+	}
+
+	file_map_mutex.Lock()
+	defer file_map_mutex.Unlock()
+	file_map[file.Fd()] = file
+	return file.Fd()
 }