Wrapper for simple filters. More...

#include "simple_private.h"

Functions
static lzma_ret	copy_or_code (lzma_simple_coder coder, const 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)
	Copied or encodes/decodes more data to out[]. More...

static size_t	call_filter (lzma_simple_coder coder, uint8_t buffer, size_t size)

static lzma_ret	simple_code (void coder_ptr, const 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)

static void	simple_coder_end (void coder_ptr, const lzma_allocator allocator)

static lzma_ret	simple_coder_update (void coder_ptr, const lzma_allocator allocator, const lzma_filter filters_null lzma_attribute((__unused__)), const lzma_filter reversed_filters)

lzma_ret	lzma_simple_coder_init (lzma_next_coder next, const lzma_allocator allocator, const lzma_filter_info filters, size_t(filter)(void 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)

Detailed Description

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.

Definition in file simple_coder.c.

Function Documentation

◆ call_filter()

static size_t call_filter	(	lzma_simple_coder *	coder,
		uint8_t *	buffer,
		size_t	size
	)

static

Definition at line 58 of file simple_coder.c.

 {
     const size_t filtered = coder->filter(coder->simple,
             coder->now_pos, coder->is_encoder,
             buffer, size);
     coder->now_pos += filtered;
     return filtered;
 }

References lzma_simple_coder::filter, lzma_simple_coder::is_encoder, lzma_simple_coder::now_pos, and lzma_simple_coder::simple.

Referenced by simple_code().

◆ copy_or_code()

static lzma_ret copy_or_code	(	lzma_simple_coder *	coder,
		const 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
	)

static

Copied or encodes/decodes more data to out[].

Definition at line 21 of file simple_coder.c.

 {
     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.
         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;
 }

References test-lz4-speed::action, allocator, assert(), lzma_next_coder_s::code, lzma_next_coder_s::coder, lzma_simple_coder::end_was_reached, in, in_pos, in_size, lzma_simple_coder::is_encoder, lzma_bufcpy(), LZMA_FINISH, LZMA_OK, LZMA_STREAM_END, lzma_simple_coder::next, NULL, out, and out_pos.

Referenced by simple_code().

◆ lzma_simple_coder_init()

lzma_ret lzma_simple_coder_init	(	lzma_next_coder *	next,
		const lzma_allocator *	allocator,
		const lzma_filter_info *	filters,
		size_t()(void simple, uint32_t now_pos, bool is_encoder, uint8_t *buffer, size_t size)	filter,
		size_t	simple_size,
		size_t	unfiltered_max,
		uint32_t	alignment,
		bool	is_encoder
	)

Definition at line 235 of file simple_coder.c.

 {
     // Allocate memory for the lzma_simple_coder structure if needed.
     lzma_simple_coder *coder = next->coder;
     if (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.
         coder = lzma_alloc(sizeof(lzma_simple_coder)
                 + 2 * unfiltered_max, allocator);
         if (coder == NULL)
             return LZMA_MEM_ERROR;
  
         next->coder = coder;
         next->code = &simple_code;
         next->end = &simple_coder_end;
         next->update = &simple_coder_update;
  
         coder->next = LZMA_NEXT_CODER_INIT;
         coder->filter = filter;
         coder->allocated = 2 * unfiltered_max;
  
         // Allocate memory for filter-specific data structure.
         if (simple_size > 0) {
             coder->simple = lzma_alloc(simple_size, allocator);
             if (coder->simple == NULL)
                 return LZMA_MEM_ERROR;
         } else {
             coder->simple = NULL;
         }
     }
  
     if (filters[0].options != NULL) {
         const lzma_options_bcj *simple = filters[0].options;
         coder->now_pos = simple->start_offset;
         if (coder->now_pos & (alignment - 1))
             return LZMA_OPTIONS_ERROR;
     } else {
         coder->now_pos = 0;
     }
  
     // Reset variables.
     coder->is_encoder = is_encoder;
     coder->end_was_reached = false;
     coder->pos = 0;
     coder->filtered = 0;
     coder->size = 0;
  
     return lzma_next_filter_init(&coder->next, allocator, filters + 1);
 }

Referenced by arm_coder_init(), armthumb_coder_init(), ia64_coder_init(), powerpc_coder_init(), sparc_coder_init(), and x86_coder_init().

◆ simple_code()

static lzma_ret simple_code	(	void *	coder_ptr,
		const 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
	)

static

Definition at line 69 of file simple_coder.c.

 {
     lzma_simple_coder *coder = coder_ptr;
  
     // 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 || buf_avail == 0) {
         // 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.
         //
         // Do the memcpy() conditionally because out can be NULL
         // (in which case buf_avail is always 0). Calling memcpy()
         // with a null-pointer is undefined even if the third
         // argument is 0.
         if (buf_avail > 0)
             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;
 }

References test-lz4-speed::action, lzma_simple_coder::allocated, allocator, assert(), lzma_simple_coder::buffer, call_filter(), copy_or_code(), lzma_simple_coder::end_was_reached, lzma_simple_coder::filtered, in, in_pos, in_size, lzma_bufcpy(), LZMA_OK, LZMA_OPTIONS_ERROR, LZMA_STREAM_END, LZMA_SYNC_FLUSH, memcpy(), out, out_pos, lzma_simple_coder::pos, and lzma_simple_coder::size.

Referenced by lzma_simple_coder_init().

◆ simple_coder_end()

static void simple_coder_end	(	void *	coder_ptr,
		const lzma_allocator *	allocator
	)

static

Definition at line 211 of file simple_coder.c.

 {
     lzma_simple_coder *coder = coder_ptr;
     lzma_next_end(&coder->next, allocator);
     lzma_free(coder->simple, allocator);
     lzma_free(coder, allocator);
     return;
 }

References allocator, lzma_free(), lzma_next_end(), lzma_simple_coder::next, and lzma_simple_coder::simple.

Referenced by lzma_simple_coder_init().

◆ simple_coder_update()

static lzma_ret simple_coder_update	(	void *	coder_ptr,
		const lzma_allocator *	allocator,
		const lzma_filter *filters_null	lzma_attribute(__unused__),
		const lzma_filter *	reversed_filters
	)

static

Definition at line 222 of file simple_coder.c.

 {
     lzma_simple_coder *coder = coder_ptr;
  
     // No update support, just call the next filter in the chain.
     return lzma_next_filter_update(
             &coder->next, allocator, reversed_filters + 1);
 }

References allocator, lzma_next_filter_update(), and lzma_simple_coder::next.

Referenced by lzma_simple_coder_init().

Functions

Detailed Description

Function Documentation

◆ call_filter()

◆ copy_or_code()

◆ lzma_simple_coder_init()

◆ simple_code()

◆ simple_coder_end()

◆ simple_coder_update()