created LZ4_initStream()

- promoted LZ4_resetStream_fast() to stable
- moved LZ4_resetStream() into deprecate, but without triggering a compiler warning
- update all sources to no longer rely on LZ4_resetStream()

note : LZ4_initStream() proposal is slightly different :
it's able to initialize any buffer, provided that it's large enough.
To this end, it accepts a void*, and returns an LZ4_stream_t*.

1 files changed, 12 insertions, 5 deletions

diff --git a/lib/lz4.c b/lib/lz4.c
index df92162..e0fcf0f 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1125,9 +1125,8 @@ _failure:
 
 int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
 {
-    LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
+    LZ4_stream_t_internal* const ctx = & LZ4_initStream(state, sizeof(LZ4_stream_t)) -> internal_donotuse;
     if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
-    LZ4_resetStream((LZ4_stream_t*)state);
     if (maxOutputSize >= LZ4_compressBound(inputSize)) {
         if (inputSize < LZ4_64Klimit) {
             return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
@@ -1221,7 +1220,7 @@ int LZ4_compress_default(const char* src, char* dst, int srcSize, int maxOutputS
 int LZ4_compress_fast_force(const char* src, char* dst, int srcSize, int dstCapacity, int acceleration)
 {
     LZ4_stream_t ctx;
-    LZ4_resetStream(&ctx);
+    LZ4_initStream(&ctx, sizeof(ctx));
 
     if (srcSize < LZ4_64Klimit) {
         return LZ4_compress_generic(&ctx.internal_donotuse, src, dst, srcSize, NULL, dstCapacity, limitedOutput, byU16,    noDict, noDictIssue, acceleration);
@@ -1237,7 +1236,7 @@ int LZ4_compress_fast_force(const char* src, char* dst, int srcSize, int dstCapa
  * _continue() call without resetting it. */
 static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
 {
-    LZ4_resetStream(state);
+    LZ4_initStream(state, sizeof (*state));
 
     if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) {  /* compression success is guaranteed */
         return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1);
@@ -1281,10 +1280,18 @@ LZ4_stream_t* LZ4_createStream(void)
     LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal));    /* A compilation error here means LZ4_STREAMSIZE is not large enough */
     DEBUGLOG(4, "LZ4_createStream %p", lz4s);
     if (lz4s == NULL) return NULL;
-    LZ4_resetStream(lz4s);
+    LZ4_initStream(lz4s, sizeof(*lz4s));
     return lz4s;
 }
 
+LZ4_stream_t* LZ4_initStream (void* buffer, size_t size)
+{
+    DEBUGLOG(5, "LZ4_initStream");
+    if (size < sizeof(LZ4_stream_t)) return NULL;
+    MEM_INIT(buffer, 0, sizeof(LZ4_stream_t));
+    return (LZ4_stream_t*)buffer;
+}
+
 void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
 {
     DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream);