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/*
See license.txt in the root of this project.
*/
# include <stdlib.h>
# include "luametatex.h"
# define LZ4F_VERSION 100 /* used to check for an incompatible API breaking change */
typedef struct lz4lib_state_info {
int initialized;
int padding;
int (*LZ4_compressBound) (int inputSize);
int (*LZ4_compress_fast) (const char *src, char *dst, int srcSize, int dstCapacity, int acceleration);
int (*LZ4_decompress_safe) (const char *src, char *dst, int compressedSize, int dstCapacity);
size_t (*LZ4F_compressFrameBound) (size_t srcSize, void *);
size_t (*LZ4F_compressFrame) (void *dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, void *);
unsigned (*LZ4F_isError) (int code);
int (*LZ4F_createDecompressionContext) (void **dctxPtr, unsigned version);
int (*LZ4F_freeDecompressionContext) (void *dctx);
size_t (*LZ4F_decompress) (void *dctx, void *dstBuffer, size_t *dstSizePtr, const void *srcBuffer, size_t *srcSizePtr, void *);
} lz4lib_state_info;
static lz4lib_state_info lz4lib_state = {
.initialized = 0,
.padding = 0,
.LZ4_compressBound = NULL,
.LZ4_compress_fast = NULL,
.LZ4_decompress_safe = NULL,
.LZ4F_compressFrameBound = NULL,
.LZ4F_compressFrame = NULL,
.LZ4F_isError = NULL,
.LZ4F_createDecompressionContext = NULL,
.LZ4F_freeDecompressionContext = NULL,
.LZ4F_decompress = NULL,
};
static int lz4lib_compress(lua_State *L)
{
if (lz4lib_state.initialized) {
size_t sourcesize = 0;
const char *source = luaL_checklstring(L, 1, &sourcesize);
lua_Integer acceleration = luaL_optinteger(L, 2, 1);
size_t targetsize = lz4lib_state.LZ4_compressBound((int) sourcesize);
luaL_Buffer buffer;
char *target = luaL_buffinitsize(L, &buffer, targetsize);
int result = lz4lib_state.LZ4_compress_fast(source, target, (int) sourcesize, (int) targetsize, (int) acceleration);
if (result > 0) {
luaL_pushresultsize(&buffer, result);
} else {
lua_pushnil(L);
}
}
return 1;
}
/*
There is no info about the target size so we don't provide a decompress function. Either use
the frame variant or save and restore the targetsize,
static int lz4lib_decompress(lua_State *L)
{
lua_pushnil(L);
return 1;
}
*/
static int lz4lib_decompresssize(lua_State *L)
{
if (lz4lib_state.initialized) {
size_t sourcesize = 0;
size_t targetsize = luaL_checkinteger(L, 2);
const char *source = luaL_checklstring(L, 1, &sourcesize);
if (source && targetsize > 0) {
luaL_Buffer buffer;
char *target = luaL_buffinitsize(L, &buffer, targetsize);
int result = lz4lib_state.LZ4_decompress_safe(source, target, (int) sourcesize, (int) targetsize);
if (result > 0) {
luaL_pushresultsize(&buffer, result);
} else {
lua_pushnil(L);
}
} else {
lua_pushnil(L);
}
}
return 1;
}
static int lz4lib_framecompress(lua_State *L)
{
if (lz4lib_state.initialized) {
size_t sourcesize = 0;
const char *source = luaL_checklstring(L, 1, &sourcesize);
luaL_Buffer buffer;
size_t targetsize = lz4lib_state.LZ4F_compressFrameBound(sourcesize, NULL);
char *target = luaL_buffinitsize(L, &buffer, targetsize);
size_t result = lz4lib_state.LZ4F_compressFrame(target, targetsize, source, sourcesize, NULL);
luaL_pushresultsize(&buffer, result);
}
return 1;
}
static int lz4lib_framedecompress(lua_State *L)
{
if (lz4lib_state.initialized) {
size_t sourcesize = 0;
const char *source = luaL_checklstring(L, 1, &sourcesize);
if (source) {
void *context = NULL;
int errorcode = lz4lib_state.LZ4F_createDecompressionContext(&context, LZ4F_VERSION);
if (lz4lib_state.LZ4F_isError(errorcode)) {
lua_pushnil(L);
} else {
luaL_Buffer buffer;
luaL_buffinit(L, &buffer);
while (1) {
size_t targetsize = 0xFFFF;
char *target = luaL_prepbuffsize(&buffer, targetsize);
size_t consumed = sourcesize;
size_t errorcode = lz4lib_state.LZ4F_decompress(context, target, &targetsize, source, &consumed, NULL);
if (lz4lib_state.LZ4F_isError((int) errorcode)) {
lua_pushnil(L);
break;
} else if (targetsize == 0) {
luaL_pushresult(&buffer);
break;
} else {
luaL_addsize(&buffer, targetsize);
sourcesize -= consumed;
source += consumed;
}
}
}
if (context) {
lz4lib_state.LZ4F_freeDecompressionContext(context);
}
} else {
lua_pushnil(L);
}
}
return 1;
}
static int lz4lib_initialize(lua_State *L)
{
if (! lz4lib_state.initialized) {
const char *filename = lua_tostring(L, 1);
if (filename) {
lmt_library lib = lmt_library_load(filename);
lz4lib_state.LZ4_compressBound = lmt_library_find(lib, "LZ4_compressBound");
lz4lib_state.LZ4_compress_fast = lmt_library_find(lib, "LZ4_compress_fast");
lz4lib_state.LZ4_decompress_safe = lmt_library_find(lib, "LZ4_decompress_safe");
lz4lib_state.LZ4F_compressFrameBound = lmt_library_find(lib, "LZ4F_compressFrameBound");
lz4lib_state.LZ4F_compressFrame = lmt_library_find(lib, "LZ4F_compressFrame");
lz4lib_state.LZ4F_isError = lmt_library_find(lib, "LZ4F_isError");
lz4lib_state.LZ4F_createDecompressionContext = lmt_library_find(lib, "LZ4F_createDecompressionContext");
lz4lib_state.LZ4F_freeDecompressionContext = lmt_library_find(lib, "LZ4F_freeDecompressionContext");
lz4lib_state.LZ4F_decompress = lmt_library_find(lib, "LZ4F_decompress");
lz4lib_state.initialized = lmt_library_okay(lib);
}
}
lua_pushboolean(L, lz4lib_state.initialized);
return 1;
}
static struct luaL_Reg lz4lib_function_list[] = {
{ "initialize", lz4lib_initialize },
{ "compress", lz4lib_compress },
/* { "decompress", lz4lib_decompress }, */
{ "decompresssize", lz4lib_decompresssize },
{ "framecompress", lz4lib_framecompress },
{ "framedecompress", lz4lib_framedecompress },
{ NULL, NULL },
};
int luaopen_lz4(lua_State * L)
{
lmt_library_register(L, "lz4", lz4lib_function_list);
return 0;
}
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