auto_decoder.c File Reference

Autodetect between .xz Stream and .lzma (LZMA_Alone) formats. More...

#include "stream_decoder.h"
#include "alone_decoder.h"

Go to the source code of this file.

Classes
struct	lzma_auto_coder

Functions
static lzma_ret	auto_decode (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	auto_decoder_end (void *coder_ptr, const lzma_allocator *allocator)
static lzma_check	auto_decoder_get_check (const void *coder_ptr)
static lzma_ret	auto_decoder_memconfig (void *coder_ptr, uint64_t *memusage, uint64_t *old_memlimit, uint64_t new_memlimit)
static lzma_ret	auto_decoder_init (lzma_next_coder *next, const lzma_allocator *allocator, uint64_t memlimit, uint32_t flags)
	LZMA_API (lzma_ret)

Detailed Description

Autodetect between .xz Stream and .lzma (LZMA_Alone) formats.

Definition in file auto_decoder.c.

Function Documentation

auto_decode()

static lzma_ret auto_decode ( 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 33 of file auto_decoder.c.

{
    lzma_auto_coder *coder = coder_ptr;
 
    switch (coder->sequence) {
    case SEQ_INIT:
        if (*in_pos >= in_size)
            return LZMA_OK;
 
        // Update the sequence now, because we want to continue from
        // SEQ_CODE even if we return some LZMA_*_CHECK.
        coder->sequence = SEQ_CODE;
 
        // Detect the file format. For now this is simple, since if
        // it doesn't start with 0xFD (the first magic byte of the
        // new format), it has to be LZMA_Alone, or something that
        // we don't support at all.
        if (in[*in_pos] == 0xFD) {
            return_if_error(lzma_stream_decoder_init(
                    &coder->next, allocator,
                    coder->memlimit, coder->flags));
        } else {
            return_if_error(lzma_alone_decoder_init(&coder->next,
                    allocator, coder->memlimit, true));
 
            // If the application wants to know about missing
            // integrity check or about the check in general, we
            // need to handle it here, because LZMA_Alone decoder
            // doesn't accept any flags.
            if (coder->flags & LZMA_TELL_NO_CHECK)
                return LZMA_NO_CHECK;
 
            if (coder->flags & LZMA_TELL_ANY_CHECK)
                return LZMA_GET_CHECK;
        }
 
    // Fall through
 
    case SEQ_CODE: {
        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
                || (coder->flags & LZMA_CONCATENATED) == 0)
            return ret;
 
        coder->sequence = SEQ_FINISH;
    }
 
    // Fall through
 
    case SEQ_FINISH:
        // When LZMA_DECODE_CONCATENATED was used and we were decoding
        // LZMA_Alone file, we need to check check that there is no
        // trailing garbage and wait for LZMA_FINISH.
        if (*in_pos < in_size)
            return LZMA_DATA_ERROR;
 
        return action == LZMA_FINISH ? LZMA_STREAM_END : LZMA_OK;
 
    default:
        assert(0);
        return LZMA_PROG_ERROR;
    }
}

References test-lz4-speed::action, allocator, assert(), lzma_next_coder_s::code, lzma_next_coder_s::coder, lzma_auto_coder::flags, in, in_pos, in_size, lzma_alone_decoder_init(), LZMA_CONCATENATED, LZMA_DATA_ERROR, LZMA_FINISH, LZMA_GET_CHECK, LZMA_NO_CHECK, LZMA_OK, LZMA_PROG_ERROR, lzma_stream_decoder_init(), LZMA_STREAM_END, LZMA_TELL_ANY_CHECK, LZMA_TELL_NO_CHECK, lzma_auto_coder::memlimit, lzma_auto_coder::next, out, out_pos, return_if_error, and lzma_auto_coder::sequence.

Referenced by auto_decoder_init().

auto_decoder_end()

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

static

Definition at line 105 of file auto_decoder.c.

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

References allocator, lzma_free(), lzma_next_end(), and lzma_auto_coder::next.

Referenced by auto_decoder_init().

auto_decoder_get_check()

static lzma_check auto_decoder_get_check ( const void *  coder_ptr )

static

Definition at line 115 of file auto_decoder.c.

{
    const lzma_auto_coder *coder = coder_ptr;
 
    // It is LZMA_Alone if get_check is NULL.
    return coder->next.get_check == NULL ? LZMA_CHECK_NONE
            : coder->next.get_check(coder->next.coder);
}

References lzma_next_coder_s::coder, lzma_next_coder_s::get_check, LZMA_CHECK_NONE, lzma_auto_coder::next, and NULL.

Referenced by auto_decoder_init().

auto_decoder_init()

static lzma_ret auto_decoder_init ( lzma_next_coder *  next, const lzma_allocator *  allocator, uint64_t  memlimit, uint32_t  flags  )

static

Definition at line 156 of file auto_decoder.c.

{
    lzma_next_coder_init(&auto_decoder_init, next, allocator);
 
    if (flags & ~LZMA_SUPPORTED_FLAGS)
        return LZMA_OPTIONS_ERROR;
 
    lzma_auto_coder *coder = next->coder;
    if (coder == NULL) {
        coder = lzma_alloc(sizeof(lzma_auto_coder), allocator);
        if (coder == NULL)
            return LZMA_MEM_ERROR;
 
        next->coder = coder;
        next->code = &auto_decode;
        next->end = &auto_decoder_end;
        next->get_check = &auto_decoder_get_check;
        next->memconfig = &auto_decoder_memconfig;
        coder->next = LZMA_NEXT_CODER_INIT;
    }
 
    coder->memlimit = my_max(1, memlimit);
    coder->flags = flags;
    coder->sequence = SEQ_INIT;
 
    return LZMA_OK;
}

References allocator, auto_decode(), auto_decoder_end(), auto_decoder_get_check(), auto_decoder_memconfig(), lzma_next_coder_s::code, lzma_next_coder_s::coder, lzma_next_coder_s::end, flags, lzma_auto_coder::flags, lzma_next_coder_s::get_check, lzma_alloc(), LZMA_MEM_ERROR, LZMA_NEXT_CODER_INIT, lzma_next_coder_init, LZMA_OK, LZMA_OPTIONS_ERROR, LZMA_SUPPORTED_FLAGS, lzma_next_coder_s::memconfig, memlimit, lzma_auto_coder::memlimit, my_max, lzma_auto_coder::next, NULL, and lzma_auto_coder::sequence.

Referenced by LZMA_API().

auto_decoder_memconfig()

static lzma_ret auto_decoder_memconfig ( void *  coder_ptr, uint64_t *  memusage, uint64_t *  old_memlimit, uint64_t  new_memlimit  )

static

Definition at line 126 of file auto_decoder.c.

{
    lzma_auto_coder *coder = coder_ptr;
 
    lzma_ret ret;
 
    if (coder->next.memconfig != NULL) {
        ret = coder->next.memconfig(coder->next.coder,
                memusage, old_memlimit, new_memlimit);
        assert(*old_memlimit == coder->memlimit);
    } else {
        // No coder is configured yet. Use the base value as
        // the current memory usage.
        *memusage = LZMA_MEMUSAGE_BASE;
        *old_memlimit = coder->memlimit;
 
        ret = LZMA_OK;
        if (new_memlimit != 0 && new_memlimit < *memusage)
            ret = LZMA_MEMLIMIT_ERROR;
    }
 
    if (ret == LZMA_OK && new_memlimit != 0)
        coder->memlimit = new_memlimit;
 
    return ret;
}

References assert(), lzma_next_coder_s::coder, LZMA_MEMLIMIT_ERROR, LZMA_MEMUSAGE_BASE, LZMA_OK, lzma_next_coder_s::memconfig, lzma_auto_coder::memlimit, lzma_auto_coder::next, and NULL.

Referenced by auto_decoder_init().

LZMA_API()

LZMA_API

(

lzma_ret

)

Definition at line 186 of file auto_decoder.c.

{
    lzma_next_strm_init(auto_decoder_init, strm, memlimit, flags);
 
    strm->internal->supported_actions[LZMA_RUN] = true;
    strm->internal->supported_actions[LZMA_FINISH] = true;
 
    return LZMA_OK;
}

References auto_decoder_init(), flags, lzma_stream::internal, LZMA_FINISH, lzma_next_strm_init, LZMA_OK, LZMA_RUN, memlimit, strm, and lzma_internal_s::supported_actions.