1 files changed, 118 insertions, 0 deletions
diff --git a/source/luametatex/source/luaoptional/lmtzstd.c b/source/luametatex/source/luaoptional/lmtzstd.c
new file mode 100644
index 000000000..ebb188d54
--- /dev/null
+++ b/source/luametatex/source/luaoptional/lmtzstd.c
@@ -0,0 +1,118 @@
+/*
+    See license.txt in the root of this project.
+*/
+
+# include "luametatex.h"
+# include "lmtoptional.h"
+
+# define ZSTD_DEFAULTCLEVEL 3
+
+typedef struct zstdlib_state_info {
+
+    int initialized;
+    int padding;
+
+    size_t      (*ZSTD_compressBound)           (size_t srcSize);
+    size_t      (*ZSTD_getFrameContentSize)     (const void *, size_t);
+    size_t      (*ZSTD_compress)                (void *dst, size_t dstCapacity, const void *src, size_t srcSize, int compressionLevel);
+    size_t      (*ZSTD_decompress)              (void *dst, size_t dstCapacity, const void *src, size_t compressedSize);
+ /* int         (*ZSTD_minCLevel)               (void);        */
+ /* int         (*ZSTD_maxCLevel)               (void);        */
+ /* unsigned    (*ZSTD_isError)                 (size_t code); */
+ /* const char *(*ZSTD_getErrorName)            (size_t code); */
+
+} zstdlib_state_info;
+
+static zstdlib_state_info zstdlib_state = {
+
+    .initialized              = 0,
+    .padding                  = 0,
+
+    .ZSTD_compressBound       = NULL,
+    .ZSTD_getFrameContentSize = NULL,
+    .ZSTD_compress            = NULL,
+    .ZSTD_decompress          = NULL,
+ /* .ZSTD_minCLevel           = NULL, */
+ /* .ZSTD_maxCLevel           = NULL, */
+ /* .ZSTD_isError             = NULL, */
+ /* .ZSTD_getErrorName        = NULL, */
+
+};
+
+static int zstdlib_compress(lua_State *L)
+{
+    if (zstdlib_state.initialized) {
+        size_t sourcesize = 0;
+        const char *source = luaL_checklstring(L, 1, &sourcesize);
+        int level = lmt_optinteger(L, 2, ZSTD_DEFAULTCLEVEL);
+        size_t targetsize = zstdlib_state.ZSTD_compressBound(sourcesize);
+        luaL_Buffer buffer;
+        char *target = luaL_buffinitsize(L, &buffer, targetsize);
+        size_t result = zstdlib_state.ZSTD_compress(target, targetsize, source, sourcesize, level);
+        if (result > 0) {
+            luaL_pushresultsize(&buffer, result);
+        } else {
+            lua_pushnil(L);
+        }
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+static int zstdlib_decompress(lua_State *L)
+{
+    if (zstdlib_state.initialized) {
+        size_t sourcesize = 0;
+        const char *source = luaL_checklstring(L, 1, &sourcesize);
+        size_t targetsize = zstdlib_state.ZSTD_getFrameContentSize(source, sourcesize);
+        luaL_Buffer buffer;
+        char *target = luaL_buffinitsize(L, &buffer, targetsize);
+        size_t result = zstdlib_state.ZSTD_decompress(target, targetsize, source, sourcesize);
+        if (result > 0) {
+            luaL_pushresultsize(&buffer, result);
+        } else {
+            lua_pushnil(L);
+        }
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+static int zstdlib_initialize(lua_State *L)
+{
+    if (! zstdlib_state.initialized) {
+        const char *filename = lua_tostring(L, 1);
+        if (filename) {
+
+            lmt_library lib = lmt_library_load(filename);
+
+            zstdlib_state.ZSTD_compressBound       = lmt_library_find(lib, "ZSTD_compressBound");
+            zstdlib_state.ZSTD_getFrameContentSize = lmt_library_find(lib, "ZSTD_getFrameContentSize");
+            zstdlib_state.ZSTD_compress            = lmt_library_find(lib, "ZSTD_compress");
+            zstdlib_state.ZSTD_decompress          = lmt_library_find(lib, "ZSTD_decompress");
+         /* zstdlib_state.ZSTD_minCLevel           = lmt_library_find(lib, "ZSTD_minCLevel"); */
+         /* zstdlib_state.ZSTD_maxCLevel           = lmt_library_find(lib, "ZSTD_maxCLevel"); */
+         /* zstdlib_state.ZSTD_isError             = lmt_library_find(lib, "ZSTD_isError"); */
+         /* zstdlib_state.ZSTD_getErrorName        = lmt_library_find(lib, "ZSTD_getErrorName"); */
+
+            zstdlib_state.initialized = lmt_library_okay(lib);
+        }
+    }
+    lua_pushboolean(L, zstdlib_state.initialized);
+    return 1;
+}
+
+static struct luaL_Reg zstdlib_function_list[] = {
+    { "initialize", zstdlib_initialize },
+    { "compress",   zstdlib_compress   },
+    { "decompress", zstdlib_decompress },
+    { NULL,         NULL               },
+};
+
+int luaopen_zstd(lua_State * L)
+{
+    lmt_library_register(L, "zstd", zstdlib_function_list);
+    return 0;
+}