/* SQLITE_KV_TRACE() is used for tracing calls to kvstorage routines. */
#if 0
-#define SQLITE_KV_TRACE(X) printf X;
+#define SQLITE_KV_TRACE(X) printf X
#else
#define SQLITE_KV_TRACE(X)
#endif
/* SQLITE_KV_LOG() is used for tracing calls to the VFS interface */
#if 0
-#define SQLITE_KV_LOG(X) printf X;
+#define SQLITE_KV_LOG(X) printf X
#else
#define SQLITE_KV_LOG(X)
#endif
/* Forward declarations for the low-level storage engine
*/
+static int kvstorageWrite(const char*, const char *zKey, const char *zData);
+static int kvstorageDelete(const char*, const char *zKey);
+static int kvstorageRead(const char*, const char *zKey, char *zBuf, int nBuf);
#define KVSTORAGE_KEY_SZ 32
/* Expand the key name with an appropriate prefix and put the result
sqlite3_snprintf(KVSTORAGE_KEY_SZ, zKeyOut, "kvvfs-%s-%s", zClass, zKeyIn);
}
-#ifdef __EMSCRIPTEN__
-/* Provide Emscripten-based impls of kvstorageWrite/Read/Delete()... */
-#include <emscripten.h>
-#include <emscripten/console.h>
-
-/*
-** WASM_KEEP is identical to EMSCRIPTEN_KEEPALIVE but is not
-** Emscripten-specific. It explicitly includes marked functions for
-** export into the target wasm file without requiring explicit listing
-** of those functions in Emscripten's -sEXPORTED_FUNCTIONS=... list
-** (or equivalent in other build platforms). Any function with neither
-** this attribute nor which is listed as an explicit export will not
-** be exported from the wasm file (but may still be used internally
-** within the wasm file).
-**
-** The functions in this filewhich require exporting are marked with
-** this flag. They may also be added to any explicit build-time export
-** list but need not be. All of these APIs are intended for use only
-** within the project's own JS/WASM code, and not by client code, so
-** an argument can be made for reducing their visibility by not
-** including them in any build-time export lists.
-**
-** 2022-09-11: it's not yet _proven_ that this approach works in
-** non-Emscripten builds. If not, such builds will need to export
-** those using the --export=... wasm-ld flag (or equivalent). As of
-** this writing we are tied to Emscripten for various reasons
-** and cannot test the library with other build environments.
-*/
-#define WASM_KEEP __attribute__((used,visibility("default")))
-/*
-** An internal level of indirection for accessing the static
-** kvstorageMakeKey() from EM_JS()-generated functions. This must be
-** made available for export via Emscripten but is not intended to be
-** used from client code. If called with a NULL zKeyOut it is a no-op.
-** It returns KVSTORAGE_KEY_SZ, so JS code (which cannot see that
-** constant) may call it with NULL arguments to get the size of the
-** allocation they'll need for a kvvfs key.
-**
-** Maintenance reminder: Emscripten will install this in the Module
-** init scope and will prefix its name with "_".
-*/
-WASM_KEEP
-int sqlite3_wasm__kvvfsMakeKey(const char *zClass, const char *zKeyIn,
- char *zKeyOut){
- if( 0!=zKeyOut ) kvstorageMakeKey(zClass, zKeyIn, zKeyOut);
- return KVSTORAGE_KEY_SZ;
-}
-/*
-** Internal helper for kvstorageWrite/Read/Delete() which creates a
-** storage key for the given zClass/zKeyIn combination. Returns a
-** pointer to the key: a C string allocated on the WASM stack, or 0 if
-** allocation fails. It is up to the caller to save/restore the stack
-** before/after this operation.
-*/
-EM_JS(const char *, kvstorageMakeKeyOnJSStack,
- (const char *zClass, const char *zKeyIn),{
- if( 0==zClass || 0==zKeyIn) return 0;
- const zXKey = stackAlloc(_sqlite3_wasm__kvvfsMakeKey(0,0,0));
- if(zXKey) _sqlite3_wasm__kvvfsMakeKey(zClass, zKeyIn, zXKey);
- return zXKey;
-});
-
-/*
-** JS impl of kvstorageWrite(). Main docs are in the C impl. This impl
-** writes zData to the global sessionStorage (if zClass starts with
-** 's') or localStorage, using a storage key derived from zClass and
-** zKey.
-*/
-EM_JS(int, kvstorageWrite,
- (const char *zClass, const char *zKey, const char *zData),{
- const stack = stackSave();
- try {
- const zXKey = kvstorageMakeKeyOnJSStack(zClass,zKey);
- if(!zXKey) return 1/*OOM*/;
- const jKey = UTF8ToString(zXKey);
- /**
- We could simplify this function and eliminate the
- kvstorageMakeKey() symbol acrobatics if we'd simply hard-code
- the key algo into the 3 functions which need it:
-
- const jKey = "kvvfs-"+UTF8ToString(zClass)+"-"+UTF8ToString(zKey);
- */
- ((115/*=='s'*/===getValue(zClass))
- ? sessionStorage : localStorage).setItem(jKey, UTF8ToString(zData));
- }catch(e){
- console.error("kvstorageWrite()",e);
- return 1; // Can't access SQLITE_xxx from here
- }finally{
- stackRestore(stack);
- }
- return 0;
-});
-
-/*
-** JS impl of kvstorageDelete(). Main docs are in the C impl. This
-** impl generates a key derived from zClass and zKey, and removes the
-** matching entry (if any) from global sessionStorage (if zClass
-** starts with 's') or localStorage.
-*/
-EM_JS(int, kvstorageDelete,
- (const char *zClass, const char *zKey),{
- const stack = stackSave();
- try {
- const zXKey = kvstorageMakeKeyOnJSStack(zClass,zKey);
- if(!zXKey) return 1/*OOM*/;
- const jKey = UTF8ToString(zXKey);
- ((115/*=='s'*/===getValue(zClass))
- ? sessionStorage : localStorage).removeItem(jKey);
- }catch(e){
- console.error("kvstorageDelete()",e);
- return 1;
- }finally{
- stackRestore(stack);
- }
- return 0;
-});
-
-/*
-** JS impl of kvstorageRead(). Main docs are in the C impl. This impl
-** reads its data from the global sessionStorage (if zClass starts
-** with 's') or localStorage, using a storage key derived from zClass
-** and zKey.
-*/
-EM_JS(int, kvstorageRead,
- (const char *zClass, const char *zKey, char *zBuf, int nBuf),{
- const stack = stackSave();
- try {
- const zXKey = kvstorageMakeKeyOnJSStack(zClass,zKey);
- if(!zXKey) return -3/*OOM*/;
- const jKey = UTF8ToString(zXKey);
- const jV = ((115/*=='s'*/===getValue(zClass))
- ? sessionStorage : localStorage).getItem(jKey);
- if(!jV) return -1;
- const nV = jV.length /* Note that we are relying 100% on v being
- ASCII so that jV.length is equal to the
- C-string's byte length. */;
- if(nBuf<=0) return nV;
- else if(1===nBuf){
- setValue(zBuf, 0);
- return nV;
- }
- const zV = allocateUTF8OnStack(jV);
- if(nBuf > nV + 1) nBuf = nV + 1;
- HEAPU8.copyWithin(zBuf, zV, zV + nBuf - 1);
- setValue( zBuf + nBuf - 1, 0 );
- return nBuf - 1;
- }catch(e){
- console.error("kvstorageRead()",e);
- return -2;
- }finally{
- stackRestore(stack);
- }
-});
-
-/*
-** This function exists for (1) WASM testing purposes and (2) as a
-** hook to get Emscripten to export several EM_JS()-generated
-** functions (if we don't reference them from exported C functions
-** then they get stripped away at build time). It is not part of the
-** public API and its signature and semantics may change at any time.
-** It's not even part of the private API, for that matter - it's part
-** of the Emscripten C/JS/WASM glue.
-*/
-WASM_KEEP
-int sqlite3__wasm_emjs_kvvfs(int whichOp){
- int rc = 0;
- const char * zClass =
- "sezzion" /*don't collide with "session" records!*/;
- const char * zKey = "hello";
- switch( whichOp ){
- case 0: break;
- case 1:
- rc = kvstorageWrite(zClass, zKey, "world");
- break;
- case 2: {
- char buffer[128] = {0};
- char * zBuf = &buffer[0];
- rc = kvstorageRead(zClass, zKey, zBuf, (int)sizeof(buffer));
- emscripten_console_logf("kvstorageRead()=%d %s\n", rc, zBuf);
- break;
- }
- case 3:
- kvstorageDelete(zClass, zKey);
- break;
- case 4:
- kvstorageMakeKeyOnJSStack(0,0);
- break;
- default: break;
- }
- return rc;
-}
-
-#undef WASM_KEEP
-#else /* end ifdef __EMSCRIPTEN__ */
-/* Forward declarations for the low-level storage engine
-*/
-static int kvstorageWrite(const char*, const char *zKey, const char *zData);
-static int kvstorageDelete(const char*, const char *zKey);
-static int kvstorageRead(const char*, const char *zKey, char *zBuf, int nBuf);
-
/* Write content into a key. zClass is the particular namespace of the
** underlying key/value store to use - either "local" or "session".
**
return (int)n;
}
}
-#endif /* ifdef __EMSCRIPTEN__ */
+
+/*
+** An internal level of indirection which enables us to replace the
+** kvvfs i/o methods with JavaScript implementations in WASM builds.
+** Maintenance reminder: if this struct changes in any way, the JSON
+** rendering of its structure must be updated in
+** sqlite3_wasm_enum_json(). There are no binary compatibility
+** concerns, so it does not need an iVersion member. This file is
+** necessarily always compiled together with sqlite3_wasm_enum_json(),
+** and JS code dynamically creates the mapping of members based on
+** that JSON description.
+*/
+typedef struct sqlite3_kvvfs_methods sqlite3_kvvfs_methods;
+struct sqlite3_kvvfs_methods {
+ int (*xRead)(const char *zClass, const char *zKey, char *zBuf, int nBuf);
+ int (*xWrite)(const char *zClass, const char *zKey, const char *zData);
+ int (*xDelete)(const char *zClass, const char *zKey);
+ const int nKeySize;
+};
+
+/*
+** This object holds the kvvfs I/O methods which may be swapped out
+** for JavaScript-side implementations in WASM builds. In such builds
+** it cannot be const, but in native builds it should be so that
+** the compiler can hopefully optimize this level of indirection out.
+** That said, kvvfs is intended primarily for use in WASM builds.
+**
+** Note that this is not explicitly flagged as static because the
+** amalgamation build will tag it with SQLITE_PRIVATE.
+*/
+#ifndef SQLITE_WASM
+const
+#endif
+sqlite3_kvvfs_methods sqlite3KvvfsMethods = {
+kvstorageRead,
+kvstorageWrite,
+kvstorageDelete,
+KVSTORAGE_KEY_SZ
+};
/****** Utility subroutines ************************************************/
static sqlite3_int64 kvvfsReadFileSize(KVVfsFile *pFile){
char zData[50];
zData[0] = 0;
- kvstorageRead(pFile->zClass, "sz", zData, sizeof(zData)-1);
+ sqlite3KvvfsMethods.xRead(pFile->zClass, "sz", zData, sizeof(zData)-1);
return strtoll(zData, 0, 0);
}
static int kvvfsWriteFileSize(KVVfsFile *pFile, sqlite3_int64 sz){
char zData[50];
sqlite3_snprintf(sizeof(zData), zData, "%lld", sz);
- return kvstorageWrite(pFile->zClass, "sz", zData);
+ return sqlite3KvvfsMethods.xWrite(pFile->zClass, "sz", zData);
}
/****** sqlite3_io_methods methods ******************************************/
pgno = 1;
}
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
- got = kvstorageRead(pFile->zClass, zKey, aData, sizeof(aData)-1);
+ got = sqlite3KvvfsMethods.xRead(pFile->zClass, zKey, aData, sizeof(aData)-1);
if( got<0 ){
n = 0;
}else{
pgno = 1 + iOfst/iAmt;
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
kvvfsEncode(zBuf, iAmt, aData);
- if( kvstorageWrite(pFile->zClass, zKey, aData) ){
+ if( sqlite3KvvfsMethods.xWrite(pFile->zClass, zKey, aData) ){
return SQLITE_IOERR;
}
if( iOfst+iAmt > pFile->szDb ){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
SQLITE_KV_LOG(("xTruncate('%s-journal',%lld)\n", pFile->zClass, size));
assert( size==0 );
- kvstorageDelete(pFile->zClass, "jrnl");
+ sqlite3KvvfsMethods.xDelete(pFile->zClass, "jrnl");
sqlite3_free(pFile->aJrnl);
pFile->aJrnl = 0;
pFile->nJrnl = 0;
pgnoMax = 2 + pFile->szDb/pFile->szPage;
while( pgno<=pgnoMax ){
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
- kvstorageDelete(pFile->zClass, zKey);
+ sqlite3KvvfsMethods.xDelete(pFile->zClass, zKey);
pgno++;
}
pFile->szDb = size;
}while( n>0 );
zOut[i++] = ' ';
kvvfsEncode(pFile->aJrnl, pFile->nJrnl, &zOut[i]);
- i = kvstorageWrite(pFile->zClass, "jrnl", zOut);
+ i = sqlite3KvvfsMethods.xWrite(pFile->zClass, "jrnl", zOut);
sqlite3_free(zOut);
return i ? SQLITE_IOERR : SQLITE_OK;
}
*/
static int kvvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
if( strcmp(zPath, "local-journal")==0 ){
- kvstorageDelete("local", "jrnl");
+ sqlite3KvvfsMethods.xDelete("local", "jrnl");
}else
if( strcmp(zPath, "session-journal")==0 ){
- kvstorageDelete("session", "jrnl");
+ sqlite3KvvfsMethods.xDelete("session", "jrnl");
}
return SQLITE_OK;
}
){
SQLITE_KV_LOG(("xAccess(\"%s\")\n", zPath));
if( strcmp(zPath, "local-journal")==0 ){
- *pResOut = kvstorageRead("local", "jrnl", 0, 0)>0;
+ *pResOut = sqlite3KvvfsMethods.xRead("local", "jrnl", 0, 0)>0;
}else
if( strcmp(zPath, "session-journal")==0 ){
- *pResOut = kvstorageRead("session", "jrnl", 0, 0)>0;
+ *pResOut = sqlite3KvvfsMethods.xRead("session", "jrnl", 0, 0)>0;
}else
if( strcmp(zPath, "local")==0 ){
- *pResOut = kvstorageRead("local", "sz", 0, 0)>0;
+ *pResOut = sqlite3KvvfsMethods.xRead("local", "sz", 0, 0)>0;
}else
if( strcmp(zPath, "session")==0 ){
- *pResOut = kvstorageRead("session", "sz", 0, 0)>0;
+ *pResOut = sqlite3KvvfsMethods.xRead("session", "sz", 0, 0)>0;
}else
{
*pResOut = 0;
projects / thirdparty / sqlite.git / commitdiff
