| Index: xz/src/liblzma/simple/simple_coder.c
|
| ===================================================================
|
| --- xz/src/liblzma/simple/simple_coder.c (revision 0)
|
| +++ xz/src/liblzma/simple/simple_coder.c (revision 0)
|
| @@ -0,0 +1,280 @@
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +//
|
| +/// \file simple_coder.c
|
| +/// \brief Wrapper for simple filters
|
| +///
|
| +/// Simple filters don't change the size of the data i.e. number of bytes
|
| +/// in equals the number of bytes out.
|
| +//
|
| +// Author: Lasse Collin
|
| +//
|
| +// This file has been put into the public domain.
|
| +// You can do whatever you want with this file.
|
| +//
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +
|
| +#include "simple_private.h"
|
| +
|
| +
|
| +/// Copied or encodes/decodes more data to out[].
|
| +static lzma_ret
|
| +copy_or_code(lzma_coder *coder, lzma_allocator *allocator,
|
| + const uint8_t *restrict in, size_t *restrict in_pos,
|
| + size_t in_size, uint8_t *restrict out,
|
| + size_t *restrict out_pos, size_t out_size, lzma_action action)
|
| +{
|
| + assert(!coder->end_was_reached);
|
| +
|
| + if (coder->next.code == NULL) {
|
| + lzma_bufcpy(in, in_pos, in_size, out, out_pos, out_size);
|
| +
|
| + // Check if end of stream was reached.
|
| + if (coder->is_encoder && action == LZMA_FINISH
|
| + && *in_pos == in_size)
|
| + coder->end_was_reached = true;
|
| +
|
| + } else {
|
| + // Call the next coder in the chain to provide us some data.
|
| + // We don't care about uncompressed_size here, because
|
| + // the next filter in the chain will do it for us (since
|
| + // we don't change the size of the data).
|
| + const lzma_ret ret = coder->next.code(
|
| + coder->next.coder, allocator,
|
| + in, in_pos, in_size,
|
| + out, out_pos, out_size, action);
|
| +
|
| + if (ret == LZMA_STREAM_END) {
|
| + assert(!coder->is_encoder
|
| + || action == LZMA_FINISH);
|
| + coder->end_was_reached = true;
|
| +
|
| + } else if (ret != LZMA_OK) {
|
| + return ret;
|
| + }
|
| + }
|
| +
|
| + return LZMA_OK;
|
| +}
|
| +
|
| +
|
| +static size_t
|
| +call_filter(lzma_coder *coder, uint8_t *buffer, size_t size)
|
| +{
|
| + const size_t filtered = coder->filter(coder->simple,
|
| + coder->now_pos, coder->is_encoder,
|
| + buffer, size);
|
| + coder->now_pos += filtered;
|
| + return filtered;
|
| +}
|
| +
|
| +
|
| +static lzma_ret
|
| +simple_code(lzma_coder *coder, lzma_allocator *allocator,
|
| + const uint8_t *restrict in, size_t *restrict in_pos,
|
| + size_t in_size, uint8_t *restrict out,
|
| + size_t *restrict out_pos, size_t out_size, lzma_action action)
|
| +{
|
| + // TODO: Add partial support for LZMA_SYNC_FLUSH. We can support it
|
| + // in cases when the filter is able to filter everything. With most
|
| + // simple filters it can be done at offset that is a multiple of 2,
|
| + // 4, or 16. With x86 filter, it needs good luck, and thus cannot
|
| + // be made to work predictably.
|
| + if (action == LZMA_SYNC_FLUSH)
|
| + return LZMA_OPTIONS_ERROR;
|
| +
|
| + // Flush already filtered data from coder->buffer[] to out[].
|
| + if (coder->pos < coder->filtered) {
|
| + lzma_bufcpy(coder->buffer, &coder->pos, coder->filtered,
|
| + out, out_pos, out_size);
|
| +
|
| + // If we couldn't flush all the filtered data, return to
|
| + // application immediately.
|
| + if (coder->pos < coder->filtered)
|
| + return LZMA_OK;
|
| +
|
| + if (coder->end_was_reached) {
|
| + assert(coder->filtered == coder->size);
|
| + return LZMA_STREAM_END;
|
| + }
|
| + }
|
| +
|
| + // If we get here, there is no filtered data left in the buffer.
|
| + coder->filtered = 0;
|
| +
|
| + assert(!coder->end_was_reached);
|
| +
|
| + // If there is more output space left than there is unfiltered data
|
| + // in coder->buffer[], flush coder->buffer[] to out[], and copy/code
|
| + // more data to out[] hopefully filling it completely. Then filter
|
| + // the data in out[]. This step is where most of the data gets
|
| + // filtered if the buffer sizes used by the application are reasonable.
|
| + const size_t out_avail = out_size - *out_pos;
|
| + const size_t buf_avail = coder->size - coder->pos;
|
| + if (out_avail > buf_avail) {
|
| + // Store the old position so that we know from which byte
|
| + // to start filtering.
|
| + const size_t out_start = *out_pos;
|
| +
|
| + // Flush data from coder->buffer[] to out[], but don't reset
|
| + // coder->pos and coder->size yet. This way the coder can be
|
| + // restarted if the next filter in the chain returns e.g.
|
| + // LZMA_MEM_ERROR.
|
| + memcpy(out + *out_pos, coder->buffer + coder->pos, buf_avail);
|
| + *out_pos += buf_avail;
|
| +
|
| + // Copy/Encode/Decode more data to out[].
|
| + {
|
| + const lzma_ret ret = copy_or_code(coder, allocator,
|
| + in, in_pos, in_size,
|
| + out, out_pos, out_size, action);
|
| + assert(ret != LZMA_STREAM_END);
|
| + if (ret != LZMA_OK)
|
| + return ret;
|
| + }
|
| +
|
| + // Filter out[].
|
| + const size_t size = *out_pos - out_start;
|
| + const size_t filtered = call_filter(
|
| + coder, out + out_start, size);
|
| +
|
| + const size_t unfiltered = size - filtered;
|
| + assert(unfiltered <= coder->allocated / 2);
|
| +
|
| + // Now we can update coder->pos and coder->size, because
|
| + // the next coder in the chain (if any) was successful.
|
| + coder->pos = 0;
|
| + coder->size = unfiltered;
|
| +
|
| + if (coder->end_was_reached) {
|
| + // The last byte has been copied to out[] already.
|
| + // They are left as is.
|
| + coder->size = 0;
|
| +
|
| + } else if (unfiltered > 0) {
|
| + // There is unfiltered data left in out[]. Copy it to
|
| + // coder->buffer[] and rewind *out_pos appropriately.
|
| + *out_pos -= unfiltered;
|
| + memcpy(coder->buffer, out + *out_pos, unfiltered);
|
| + }
|
| + } else if (coder->pos > 0) {
|
| + memmove(coder->buffer, coder->buffer + coder->pos, buf_avail);
|
| + coder->size -= coder->pos;
|
| + coder->pos = 0;
|
| + }
|
| +
|
| + assert(coder->pos == 0);
|
| +
|
| + // If coder->buffer[] isn't empty, try to fill it by copying/decoding
|
| + // more data. Then filter coder->buffer[] and copy the successfully
|
| + // filtered data to out[]. It is probable, that some filtered and
|
| + // unfiltered data will be left to coder->buffer[].
|
| + if (coder->size > 0) {
|
| + {
|
| + const lzma_ret ret = copy_or_code(coder, allocator,
|
| + in, in_pos, in_size,
|
| + coder->buffer, &coder->size,
|
| + coder->allocated, action);
|
| + assert(ret != LZMA_STREAM_END);
|
| + if (ret != LZMA_OK)
|
| + return ret;
|
| + }
|
| +
|
| + coder->filtered = call_filter(
|
| + coder, coder->buffer, coder->size);
|
| +
|
| + // Everything is considered to be filtered if coder->buffer[]
|
| + // contains the last bytes of the data.
|
| + if (coder->end_was_reached)
|
| + coder->filtered = coder->size;
|
| +
|
| + // Flush as much as possible.
|
| + lzma_bufcpy(coder->buffer, &coder->pos, coder->filtered,
|
| + out, out_pos, out_size);
|
| + }
|
| +
|
| + // Check if we got everything done.
|
| + if (coder->end_was_reached && coder->pos == coder->size)
|
| + return LZMA_STREAM_END;
|
| +
|
| + return LZMA_OK;
|
| +}
|
| +
|
| +
|
| +static void
|
| +simple_coder_end(lzma_coder *coder, lzma_allocator *allocator)
|
| +{
|
| + lzma_next_end(&coder->next, allocator);
|
| + lzma_free(coder->simple, allocator);
|
| + lzma_free(coder, allocator);
|
| + return;
|
| +}
|
| +
|
| +
|
| +static lzma_ret
|
| +simple_coder_update(lzma_coder *coder, lzma_allocator *allocator,
|
| + const lzma_filter *filters_null lzma_attribute((unused)),
|
| + const lzma_filter *reversed_filters)
|
| +{
|
| + // No update support, just call the next filter in the chain.
|
| + return lzma_next_filter_update(
|
| + &coder->next, allocator, reversed_filters + 1);
|
| +}
|
| +
|
| +
|
| +extern lzma_ret
|
| +lzma_simple_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
|
| + const lzma_filter_info *filters,
|
| + size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
|
| + bool is_encoder, uint8_t *buffer, size_t size),
|
| + size_t simple_size, size_t unfiltered_max,
|
| + uint32_t alignment, bool is_encoder)
|
| +{
|
| + // Allocate memory for the lzma_coder structure if needed.
|
| + if (next->coder == NULL) {
|
| + // Here we allocate space also for the temporary buffer. We
|
| + // need twice the size of unfiltered_max, because then it
|
| + // is always possible to filter at least unfiltered_max bytes
|
| + // more data in coder->buffer[] if it can be filled completely.
|
| + next->coder = lzma_alloc(sizeof(lzma_coder)
|
| + + 2 * unfiltered_max, allocator);
|
| + if (next->coder == NULL)
|
| + return LZMA_MEM_ERROR;
|
| +
|
| + next->code = &simple_code;
|
| + next->end = &simple_coder_end;
|
| + next->update = &simple_coder_update;
|
| +
|
| + next->coder->next = LZMA_NEXT_CODER_INIT;
|
| + next->coder->filter = filter;
|
| + next->coder->allocated = 2 * unfiltered_max;
|
| +
|
| + // Allocate memory for filter-specific data structure.
|
| + if (simple_size > 0) {
|
| + next->coder->simple = lzma_alloc(
|
| + simple_size, allocator);
|
| + if (next->coder->simple == NULL)
|
| + return LZMA_MEM_ERROR;
|
| + } else {
|
| + next->coder->simple = NULL;
|
| + }
|
| + }
|
| +
|
| + if (filters[0].options != NULL) {
|
| + const lzma_options_bcj *simple = filters[0].options;
|
| + next->coder->now_pos = simple->start_offset;
|
| + if (next->coder->now_pos & (alignment - 1))
|
| + return LZMA_OPTIONS_ERROR;
|
| + } else {
|
| + next->coder->now_pos = 0;
|
| + }
|
| +
|
| + // Reset variables.
|
| + next->coder->is_encoder = is_encoder;
|
| + next->coder->end_was_reached = false;
|
| + next->coder->pos = 0;
|
| + next->coder->filtered = 0;
|
| + next->coder->size = 0;
|
| +
|
| + return lzma_next_filter_init(
|
| + &next->coder->next, allocator, filters + 1);
|
| +}
|
|
|
| Property changes on: xz/src/liblzma/simple/simple_coder.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|