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Improve ZIP decompression (#15220)

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This reduces the amount of memory Retroarch needs to extract a ROM file.
It will only need the size of the ROM plus 128KiB to extract the file
from the ZIP. Previously it needed as much as twice that amount if the
compression ratio was not great. This is useful on memory constrained
platforms and has no impact on platforms with plenty of memory.

Handles all cases correctly (with and without MMAP, for cores that
require fullpath or not, small and big ZIP files).
This commit is contained in:
David G. F 2023-04-25 13:17:18 +02:00 committed by GitHub
parent fc5d16f5a4
commit f13cf92341
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 124 additions and 132 deletions
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256
libretro-common/file/archive_file_zlib.c
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@ -25,12 +25,10 @@
#include <file/archive_file.h>
#include <streams/file_stream.h>
#include <streams/trans_stream.h>
#include <retro_inline.h>
#include <retro_miscellaneous.h>
#include <encodings/crc32.h>
/* Only for MAX_WBITS */
#include <zlib.h>
#ifndef CENTRAL_FILE_HEADER_SIGNATURE
@ -41,6 +39,8 @@
#define END_OF_CENTRAL_DIR_SIGNATURE 0x06054b50
#endif
#define _READ_CHUNK_SIZE (128*1024) /* Read 128KiB compressed chunks */
enum file_archive_compression_mode
{
ZIP_MODE_STORED = 0,
@ -53,8 +53,11 @@ typedef struct
uint8_t *directory;
uint8_t *directory_entry;
uint8_t *directory_end;
void *current_stream;
uint8_t *compressed_data;
uint64_t fdoffset;
uint32_t boffset, csize, usize;
unsigned cmode;
z_stream *zstream;
uint8_t *tmpbuf;
uint8_t *decompressed_data;
} zip_context_t;
@ -73,20 +76,19 @@ static INLINE uint32_t read_le(const uint8_t *data, unsigned size)
static void zip_context_free_stream(
zip_context_t *zip_context, bool keep_decompressed)
{
if (zip_context->current_stream)
if (zip_context->zstream)
{
zlib_inflate_backend.stream_free(zip_context->current_stream);
zip_context->current_stream = NULL;
inflateEnd(zip_context->zstream);
free(zip_context->zstream);
zip_context->fdoffset = 0;
zip_context->csize = 0;
zip_context->usize = 0;
zip_context->zstream = NULL;
}
if (zip_context->compressed_data)
if (zip_context->tmpbuf)
{
#ifdef HAVE_MMAP
if (!zip_context->state->archive_mmap_data)
#endif
{
free(zip_context->compressed_data);
zip_context->compressed_data = NULL;
}
free(zip_context->tmpbuf);
zip_context->tmpbuf = NULL;
}
if (zip_context->decompressed_data && !keep_decompressed)
{
@ -128,51 +130,40 @@ static bool zlib_stream_decompress_data_to_file_init(
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->fdoffset = offsetData;
zip_context->usize = size;
zip_context->csize = csize;
zip_context->boffset = 0;
zip_context->cmode = cmode;
zip_context->decompressed_data = (uint8_t*)malloc(size);
zip_context->zstream = NULL;
zip_context->tmpbuf = NULL;
if (cmode == ZIP_MODE_DEFLATED)
{
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;
/* skip over name and extra data */
filestream_seek(state->archive_file, offsetData, RETRO_VFS_SEEK_POSITION_START);
if (filestream_read(state->archive_file, zip_context->compressed_data, csize) != csize)
/* Initialize the zlib inflate machinery */
zip_context->zstream = (z_stream*)malloc(sizeof(z_stream));
zip_context->tmpbuf = malloc(_READ_CHUNK_SIZE);
zip_context->zstream->next_in = NULL;
zip_context->zstream->avail_in = 0;
zip_context->zstream->total_in = 0;
zip_context->zstream->next_out = zip_context->decompressed_data;
zip_context->zstream->avail_out = size;
zip_context->zstream->total_out = 0;
zip_context->zstream->zalloc = NULL;
zip_context->zstream->zfree = NULL;
zip_context->zstream->opaque = NULL;
if (inflateInit2(zip_context->zstream, -MAX_WBITS) != Z_OK) {
free(zip_context->zstream);
zip_context->zstream = NULL;
goto error;
}
}
switch (cmode)
{
case ZIP_MODE_STORED:
handle->data = zip_context->compressed_data;
return true;
case ZIP_MODE_DEFLATED:
zip_context->current_stream = zlib_inflate_backend.stream_new();
if (!zip_context->current_stream)
goto error;
if (zlib_inflate_backend.define)
zlib_inflate_backend.define(zip_context->current_stream, "window_bits", (uint32_t)-MAX_WBITS);
zip_context->decompressed_data = (uint8_t*)malloc(size);
if (!zip_context->decompressed_data)
goto error;
zlib_inflate_backend.set_in(zip_context->current_stream,
zip_context->compressed_data, csize);
zlib_inflate_backend.set_out(zip_context->current_stream,
zip_context->decompressed_data, size);
return true;
}
return true;
error:
zip_context_free_stream(zip_context, false);
@ -183,35 +174,84 @@ static int zlib_stream_decompress_data_to_file_iterate(
void *context, file_archive_file_handle_t *handle)
{
zip_context_t *zip_context = (zip_context_t *)context;
bool zstatus;
uint32_t rd, wn;
enum trans_stream_error terror;
struct file_archive_transfer *state = zip_context->state;
int64_t rd;
if (!zip_context->current_stream)
if (zip_context->cmode == ZIP_MODE_STORED)
{
/* file was uncompressed or decompression finished before */
return 1;
}
#ifdef HAVE_MMAP
if (zip_context->state->archive_mmap_data)
{
/* Simply copy the data to the output buffer */
memcpy(zip_context->decompressed_data,
zip_context->state->archive_mmap_data,
zip_context->usize);
}
else
#endif
{
/* Read the entire file to memory */
filestream_seek(state->archive_file, zip_context->fdoffset, RETRO_VFS_SEEK_POSITION_START);
if (filestream_read(state->archive_file,
zip_context->decompressed_data,
zip_context->usize) < 0)
return -1;
}
zstatus = zlib_inflate_backend.trans(zip_context->current_stream, false, &rd, &wn, &terror);
if (zstatus && !terror)
{
/* successfully decompressed entire file */
zip_context_free_stream(zip_context, true);
handle->data = zip_context->decompressed_data;
return 1;
}
if (!zstatus && terror != TRANS_STREAM_ERROR_BUFFER_FULL)
else if (zip_context->cmode == ZIP_MODE_DEFLATED)
{
/* error during stream processing */
zip_context_free_stream(zip_context, false);
return -1;
int to_read = MIN(zip_context->csize - zip_context->boffset, _READ_CHUNK_SIZE);
uint8_t *dptr;
if (!zip_context->zstream)
{
/* file was uncompressed or decompression finished before */
return 1;
}
#ifdef HAVE_MMAP
if (state->archive_mmap_data)
{
/* Decompress from the mapped file */
dptr = state->archive_mmap_data + (size_t)zip_context->fdoffset + zip_context->boffset;
rd = to_read;
}
else
#endif
{
/* Read some compressed data from file to the temp buffer */
filestream_seek(state->archive_file, zip_context->fdoffset + zip_context->boffset,
RETRO_VFS_SEEK_POSITION_START);
rd = filestream_read(state->archive_file, zip_context->tmpbuf, to_read);
if (rd < 0)
return -1;
dptr = zip_context->tmpbuf;
}
zip_context->boffset += rd;
zip_context->zstream->next_in = dptr;
zip_context->zstream->avail_in = rd;
if (inflate(zip_context->zstream, 0) < 0)
return -1;
if (zip_context->boffset >= zip_context->csize)
{
inflateEnd(zip_context->zstream);
free(zip_context->zstream);
zip_context->zstream = NULL;
handle->data = zip_context->decompressed_data;
return 1;
}
return 0; /* still more data to process */
}
/* still more data to process */
return 0;
/* No idea what kind of compression this is */
return -1;
}
static uint32_t zlib_stream_crc32_calculate(uint32_t crc,
@ -238,22 +278,10 @@ static bool zip_file_decompressed_handle(
{
ret = transfer->backend->stream_decompress_data_to_file_iterate(
transfer->context, handle);
if (ret < 0)
return false;
}while (ret == 0);
#if 0
handle->real_checksum = transfer->backend->stream_crc_calculate(0,
handle->data, size);
if (handle->real_checksum != crc32)
{
if (handle->data)
free(handle->data);
handle->data = NULL;
return false;
}
#endif
return true;
}
@ -314,46 +342,10 @@ static int zip_file_decompressed(
zip_context_t *zip_context = (zip_context_t *)userdata->transfer->context;
decomp_state->size = 0;
/* Unlink data buffer from context (otherwise
* it will be freed when the stream is deinitialised) */
if (handle.data == zip_context->compressed_data)
{
/* Well this is fun...
* If this is 'compressed' data (if the zip
* file was created with the '-0 store only'
* flag), and the origin file is mmapped, then
* the context compressed_data buffer cannot be
* reassigned (since it is not a traditional
* block of user-assigned memory). We have to
* create a copy of it instead... */
#ifdef HAVE_MMAP
if (zip_context->state->archive_mmap_data)
{
uint8_t *temp_buf = (uint8_t*)malloc(csize);
if (temp_buf)
{
memcpy(temp_buf, handle.data, csize);
*decomp_state->buf = temp_buf;
decomp_state->size = csize;
}
}
else
#endif
{
*decomp_state->buf = handle.data;
decomp_state->size = csize;
zip_context->compressed_data = NULL;
}
}
else if (handle.data == zip_context->decompressed_data)
{
*decomp_state->buf = handle.data;
decomp_state->size = size;
zip_context->decompressed_data = NULL;
}
*decomp_state->buf = handle.data;
decomp_state->size = size;
/* We keep the data, prevent its deallocation during free */
zip_context->decompressed_data = NULL;
handle.data = NULL;
}
}
@ -466,8 +458,8 @@ static int zip_parse_file_init(file_archive_transfer_t *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;
zip_context->current_stream = NULL;
zip_context->compressed_data = NULL;
zip_context->zstream = NULL;
zip_context->tmpbuf = NULL;
zip_context->decompressed_data = NULL;
filestream_seek(state->archive_file, directory_offset, RETRO_VFS_SEEK_POSITION_START);