Bring back MMAP support

Will be used where available for files up to 256MB

libretro-common/file/archive_file.c

@@ -32,6 +32,14 @@
 #include <lists/string_list.h>
 #include <string/stdstring.h>
 
+#ifdef HAVE_MMAP
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#endif
+
 static int file_archive_get_file_list_cb(
       const char *path,
       const char *valid_exts,
@@ -159,6 +167,25 @@ static int file_archive_parse_file_init(file_archive_transfer_t *state,
 
    state->archive_size = filestream_get_size(state->archive_file);
 
+#ifdef HAVE_MMAP
+   if (state->archive_size <= (256*1024*1024))
+   {
+      state->archive_mmap_fd = open(path, O_RDONLY);
+      if (state->archive_mmap_fd)
+      {
+         state->archive_mmap_data = (uint8_t*)mmap(NULL, (size_t)state->archive_size,
+               PROT_READ, MAP_SHARED, state->archive_mmap_fd, 0);
+
+         if (state->archive_mmap_data == (uint8_t*)MAP_FAILED)
+         {
+            close(state->archive_mmap_fd);
+            state->archive_mmap_fd = 0;
+            state->archive_mmap_data = NULL;
+         }
+      }
+   }
+#endif
+
    state->step_current = 0;
    state->step_total   = 0;
 
@@ -273,6 +300,16 @@ int file_archive_parse_file_iterate(
             state->archive_file = NULL;
          }
 
+#ifdef HAVE_MMAP
+         if (state->archive_mmap_data)
+         {
+            munmap(state->archive_mmap_data, (size_t)state->archive_size);
+            close(state->archive_mmap_fd);
+            state->archive_mmap_fd = 0;
+            state->archive_mmap_data = NULL;
+         }
+#endif
+
          if (userdata)
             userdata->transfer = NULL;
          break;
@@ -306,6 +343,10 @@ static bool file_archive_walk(const char *file, const char *valid_exts,
 
    state.type              = ARCHIVE_TRANSFER_INIT;
    state.archive_file      = NULL;
+#ifdef HAVE_MMAP
+   state.archive_mmap_fd   = 0;
+   state.archive_mmap_data = NULL;
+#endif
    state.archive_size      = 0;
    state.context           = NULL;
    state.step_total        = 0;
@@ -642,6 +683,10 @@ uint32_t file_archive_get_file_crc32(const char *path)
 
    state.type              = ARCHIVE_TRANSFER_INIT;
    state.archive_file      = NULL;
+#ifdef HAVE_MMAP
+   state.archive_mmap_fd   = 0;
+   state.archive_mmap_data = NULL;
+#endif
    state.archive_size      = 0;
    state.context           = NULL;
    state.step_total        = 0;

libretro-common/file/archive_file_zlib.c

@@ -49,7 +49,7 @@ enum file_archive_compression_mode
 
 typedef struct
 {
-   RFILE   *file;
+   struct file_archive_transfer *state;
    uint8_t *directory;
    uint8_t *directory_entry;
    uint8_t *directory_end;
@@ -79,10 +79,15 @@ static void zip_context_free_stream(
       zip_context->current_stream = NULL;
    }
    if (zip_context->compressed_data)
+   {
+#ifdef HAVE_MMAP
+      if (!zip_context->state->archive_mmap_data)
+#endif
       {
          free(zip_context->compressed_data);
          zip_context->compressed_data = NULL;
       }
+   }
    if (zip_context->decompressed_data && !keep_decompressed)
    {
       free(zip_context->decompressed_data);
@@ -95,38 +100,57 @@ static bool zlib_stream_decompress_data_to_file_init(
       const uint8_t *cdata, unsigned cmode, uint32_t csize, uint32_t size)
 {
    zip_context_t *zip_context = (zip_context_t *)context;
+   struct file_archive_transfer *state = zip_context->state;
    uint8_t local_header_buf[4];
+   uint8_t *local_header;
    uint32_t offsetNL, offsetEL;
    int64_t offsetData;
 
-   /* free previous stream if left unfinished */
+   /* free previous data and stream if left unfinished */
    zip_context_free_stream(zip_context, false);
 
+   /* seek past most of the local directory header */
+#ifdef HAVE_MMAP
+   if (state->archive_mmap_data)
+   {
+      local_header = state->archive_mmap_data + (size_t)cdata + 26;
+   }
+   else
+#endif
+   {
+      filestream_seek(state->archive_file, (int64_t)(size_t)cdata + 26, RETRO_VFS_SEEK_POSITION_START);
+      if (filestream_read(state->archive_file, local_header_buf, 4) != 4)
+         goto error;
+      local_header = local_header_buf;
+   }
+
+   offsetNL = read_le(local_header,     2); /* file name length */
+   offsetEL = read_le(local_header + 2, 2); /* extra field length */
+   offsetData = (int64_t)(size_t)cdata + 26 + 4 + offsetNL + offsetEL;
+
+#ifdef HAVE_MMAP
+   if (state->archive_mmap_data)
+   {
+      zip_context->compressed_data = state->archive_mmap_data + (size_t)offsetData;
+   }
+   else
+#endif
+   {
       /* allocate memory for the compressed data */
       zip_context->compressed_data = (uint8_t*)malloc(csize);
       if (!zip_context->compressed_data)
          goto error;
 
-   /* seek past most of the local directory header */
-   filestream_seek(zip_context->file, (int64_t)(size_t)cdata + 26, RETRO_VFS_SEEK_POSITION_START);
-   if (filestream_read(zip_context->file, local_header_buf, 4) != 4)
-      goto error;
-
-   offsetNL = read_le(local_header_buf,     2); /* file name length */
-   offsetEL = read_le(local_header_buf + 2, 2); /* extra field length */
-   offsetData = (int64_t)(size_t)cdata + 26 + 4 + offsetNL + offsetEL;
-
       /* skip over name and extra data */
-   filestream_seek(zip_context->file, offsetData, RETRO_VFS_SEEK_POSITION_START);
+      filestream_seek(state->archive_file, offsetData, RETRO_VFS_SEEK_POSITION_START);
-   if (filestream_read(zip_context->file, zip_context->compressed_data, csize) != csize)
+      if (filestream_read(state->archive_file, zip_context->compressed_data, csize) != csize)
          goto error;
+   }
 
    switch (cmode)
    {
       case ZIP_MODE_STORED:
-         zip_context->decompressed_data = zip_context->compressed_data;
+         handle->data = zip_context->compressed_data;
-         zip_context->compressed_data = NULL;
-         handle->data = zip_context->decompressed_data;
          return true;
 
      case ZIP_MODE_DEFLATED:
@@ -397,7 +421,7 @@ static int zip_parse_file_init(file_archive_transfer_t *state,
     * context and the entire directory, then read the directory.
     */
    zip_context = (zip_context_t*)malloc(sizeof(zip_context_t) + (size_t)directory_size);
-   zip_context->file              = state->archive_file;
+   zip_context->state             = state;
    zip_context->directory         = (uint8_t*)(zip_context + 1);
    zip_context->directory_entry   = zip_context->directory;
    zip_context->directory_end     = zip_context->directory + (size_t)directory_size;

libretro-common/include/file/archive_file.h

@@ -58,6 +58,10 @@ typedef struct file_archive_transfer
 {
    enum file_archive_transfer_type type;
    struct RFILE *archive_file;
+#ifdef HAVE_MMAP
+   int archive_mmap_fd;
+   uint8_t *archive_mmap_data;
+#endif
    int64_t archive_size;
    void *context;
    unsigned step_total, step_current;