sqlite: support getting time and deleting

Change-Id: I7abef164a64e2358134cbbf076adf3b225145033

misc/sqlite/sqlite3_os_go.c

@@ -118,8 +118,7 @@ static int go_vfs_open(sqlite3_vfs* vfs,
 }
 
 static int go_vfs_delete(sqlite3_vfs* vfs, const char* zName, int syncDir) {
-  fprintf(stderr, "delete: %s\n", zName);
-  return SQLITE_OK;
+  return GoVFSDelete(zName, syncDir);
 }
 
 static int go_vfs_access(sqlite3_vfs* vfs,
@@ -142,37 +141,37 @@ static int go_vfs_full_pathname(sqlite3_vfs* vfs,
 }
 
 static void* go_vfs_dl_open(sqlite3_vfs* vfs, const char* zFilename) {
-  fprintf(stderr, "go_vfs_dl_open\n");
+  fprintf(stderr, "TODO go_vfs_dl_open\n");
   return NULL;
 }
 
 static void go_vfs_dl_error(sqlite3_vfs* vfs, int nByte, char *zErrMsg) {
-  fprintf(stderr, "go_vfs_dl_error\n");
+  fprintf(stderr, "TODO go_vfs_dl_error\n");
 }
 
 static void* go_vfs_dl_sym(sqlite3_vfs* vfs,
                            void* handle,
                            const char* zSymbol) {
-  fprintf(stderr, "go_vfs_dl_sym\n");
+  fprintf(stderr, "TODO go_vfs_dl_sym\n");
   return NULL;
 }
 
 static void go_vfs_dl_close(sqlite3_vfs* vfs, void* handle) {
-  fprintf(stderr, "go_vfs_dl_close\n");
+  fprintf(stderr, "TODO go_vfs_dl_close\n");
 }
 
 static int go_vfs_randomness(sqlite3_vfs* vfs, int nByte, char *zOut) {
-  fprintf(stderr, "go_vfs_randomness\n");
+  fprintf(stderr, "TODO go_vfs_randomness\n");
   return SQLITE_OK;
 }
 
 static int go_vfs_sleep(sqlite3_vfs* vfs, int microseconds) {
-  fprintf(stderr, "go_vfs_sleep\n");
+  fprintf(stderr, "TODO go_vfs_sleep\n");
   return SQLITE_OK;
 }
 
 static int go_vfs_current_time(sqlite3_vfs* vfs, double* now) {
-  fprintf(stderr, "go_vfs_current_time\n");
+  *now = GoVFSCurrentTimeInt64() / 86400000.0;
   return SQLITE_OK;
 }
 
@@ -181,10 +180,15 @@ static int go_vfs_get_last_error(sqlite3_vfs* vfs, int foo, char* bar) {
   return SQLITE_OK;
 }
 
+static int go_vfs_current_time_int64(sqlite3_vfs* vfs, sqlite3_int64* now) {
+  *now = GoVFSCurrentTimeInt64();
+  return SQLITE_OK;
+}
+
 int sqlite3_os_init(void) {
   static sqlite3_vfs vfs;
   memset(&vfs, 0, sizeof(vfs));
-  vfs.iVersion = 1;
+  vfs.iVersion = 2;
   vfs.szOsFile = sizeof(GoFile);
   vfs.mxPathname = 512;
   vfs.pNext = NULL;
@@ -203,12 +207,9 @@ int sqlite3_os_init(void) {
   vfs.xSleep = go_vfs_sleep;
   vfs.xCurrentTime = go_vfs_current_time;
   vfs.xGetLastError = go_vfs_get_last_error;
+  /* Version 2 method */
+  vfs.xCurrentTimeInt64 = go_vfs_current_time_int64;
 #if 0
-  /*
-  ** The methods above are in version 1 of the sqlite_vfs object
-  ** definition.  Those that follow are added in version 2 or later
-  */
-  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
   /*
   ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
   ** Those below are for version 3 and greater.

misc/sqlite/vfs.go

@@ -11,6 +11,7 @@ import "C"
 import (
 	"os"
 	"sync"
+	"time"
 	"unsafe"
 )
 
@@ -165,6 +166,24 @@ func GoVFSOpen(filename *C.char, flags C.int) (fd int) {
 	return file.Fd()
 }
 
+//export GoVFSDelete
+// Returns SQLite error code to be returned by xWrite:
+//   SQLITE_OK: deleted the file
+//   SQLITE_IOERR_DELETE: failed to delete
+//   SQLITE_IOERR_DIR_FSYNC: failed to fsync dir after deleting
+func GoVFSDelete(filename *C.char, syncDir C.int) (rv int) {
+	println("deleting", C.GoString(filename), "with syncdir", syncDir)
+	if err := os.Remove(C.GoString(filename)); err != nil {
+		if pe, ok := err.(*os.PathError); ok && pe.Error == os.ENOENT {
+			return C.SQLITE_OK
+		}
+		println("delete of", C.GoString(filename), "failed:", err.String())
+		return C.SQLITE_IOERR_DELETE
+	}
+	// TODO: Support syncDir.
+	return C.SQLITE_OK
+}
+
 //export GoVFSAccess
 func GoVFSAccess(filename *C.char, flags C.int) (rv int) {
 	fi, err := os.Stat(C.GoString(filename))
@@ -186,3 +205,10 @@ func GoVFSAccess(filename *C.char, flags C.int) (rv int) {
 	}
 	return 0
 }
+
+//export GoVFSCurrentTimeInt64
+func GoVFSCurrentTimeInt64() (now int64) {
+	// Unix epoch as a Julian Day number times 86_400_000.
+	const unixEpoch = 24405875 * 8640000
+	return unixEpoch + (time.Nanoseconds() / 1000000)
+}