Making the hashing buffer reusable instead of malloc every file

platform_windows.c

@@ -375,7 +375,7 @@ void scan_folder_windows_parallel(const char *base, DirQueue *q) {
 }
 
 // ----------------------------- Hashing helpers -----------------------------
-static void xxh3_hash_file_stream(const char *path, char *out_hex) {
+static void xxh3_hash_file_stream(const char *path, char *out_hex, BYTE *buf) {
   // compute XXH3_128 over file. POSIX and Windows use standard reads in this
   // helper.
   // On Windows try to use overlapped synchronous chunked reads for higher
@@ -391,7 +391,7 @@ static void xxh3_hash_file_stream(const char *path, char *out_hex) {
   XXH3_state_t state;
   XXH3_128bits_reset(&state);
 
-  BYTE *buf = (BYTE *)malloc(READ_BLOCK);
+  // BYTE *buf = (BYTE *)malloc(READ_BLOCK);
   DWORD read = 0;
   BOOL ok;
   while (ReadFile(hFile, buf, READ_BLOCK, &read, NULL) && read > 0) {
@@ -400,7 +400,7 @@ static void xxh3_hash_file_stream(const char *path, char *out_hex) {
   }
   h = XXH3_128bits_digest(&state);
   CloseHandle(hFile);
-  free(buf);
+  // free(buf);
   snprintf(out_hex, HASH_STRLEN, "%016llx%016llx", (unsigned long long)h.high64,
            (unsigned long long)h.low64);
 }
@@ -411,6 +411,7 @@ static DWORD WINAPI hash_worker(LPVOID arg) {
   WorkerContext *ctx = (WorkerContext *)arg;
   MPMCQueue *q = ctx->queue;
   mem_arena *local_arena = ctx->arena;
+  BYTE *buf = (BYTE *)malloc(READ_BLOCK);
 
   for (;;) {
     FileEntry *fe = mpmc_pop(q);
@@ -418,7 +419,7 @@ static DWORD WINAPI hash_worker(LPVOID arg) {
       break;
 
     char hash[HASH_STRLEN];
-    xxh3_hash_file_stream(fe->path, hash);
+    xxh3_hash_file_stream(fe->path, hash, buf);
 
     char created[32], modified[32];
     format_time(fe->created_time, created, sizeof(created));
@@ -440,6 +441,7 @@ static DWORD WINAPI hash_worker(LPVOID arg) {
     free(fe->path);
     free(fe);
   }
+  free(buf);
 
   return 0;
 }