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Add lzma_filters_copy().

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This will be needed internally by liblzma once I fix
a design mistake in the encoder API. This function may
be useful to applications too so it's good to export it.
This commit is contained in:
Lasse Collin 2009-10-17 01:47:07 +03:00
parent 78e92c1847
commit 6d118a0b9d
2 changed files with 113 additions and 0 deletions
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31
src/liblzma/api/lzma/filter.h
View file

@ -94,6 +94,37 @@ extern LZMA_API(lzma_bool) lzma_filter_decoder_is_supported(lzma_vli id)
lzma_nothrow lzma_attr_const;
/**
* \brief Copy the filters array
*
* Copy the Filter IDs and filter-specific options from src to dest.
* Up to LZMA_FILTERS_MAX filters are copied, plus the terminating
* .id == LZMA_VLI_UNKNOWN. Thus, dest should have at least
* LZMA_FILTERS_MAX + 1 elements space unless the caller knows that
* src is smaller than that.
*
* Unless the filter-specific options is NULL, the Filter ID has to be
* supported by liblzma, because liblzma needs to know the size of every
* filter-specific options structure. The filter-specific options are not
* validated. If options is NULL, any unsupported Filter IDs are copied
* without returning an error.
*
* Old filter-specific options in dest are not freed, so dest doesn't
* need to be initialized by the caller in any way.
*
* If an error occurs, memory possibly already allocated by this function
* is always freed.
*
* \return - LZMA_OK
* - LZMA_MEM_ERROR
* - LZMA_OPTIONS_ERROR: Unsupported Filter ID and its options
* is not NULL.
* - LZMA_PROG_ERROR: src or dest is NULL.
*/
extern LZMA_API(lzma_ret) lzma_filters_dup(const lzma_filter *src,
lzma_filter *dest, lzma_allocator *allocator);
/**
* \brief Calculate rough memory requirements for raw encoder
*

82
src/liblzma/common/filter_common.c
View file

@ -17,6 +17,9 @@ static const struct {
/// Filter ID
lzma_vli id;
/// Size of the filter-specific options structure
size_t options_size;
/// True if it is OK to use this filter as non-last filter in
/// the chain.
bool non_last_ok;
@ -34,6 +37,7 @@ static const struct {
#if defined (HAVE_ENCODER_LZMA1) || defined(HAVE_DECODER_LZMA1)
{
.id = LZMA_FILTER_LZMA1,
.options_size = sizeof(lzma_options_lzma),
.non_last_ok = false,
.last_ok = true,
.changes_size = true,
@ -42,6 +46,7 @@ static const struct {
#ifdef HAVE_DECODER_LZMA2
{
.id = LZMA_FILTER_LZMA2,
.options_size = sizeof(lzma_options_lzma),
.non_last_ok = false,
.last_ok = true,
.changes_size = true,
@ -50,6 +55,7 @@ static const struct {
#if defined(HAVE_ENCODER_SUBBLOCK) || defined(HAVE_DECODER_SUBBLOCK)
{
.id = LZMA_FILTER_SUBBLOCK,
.options_size = sizeof(lzma_options_subblock),
.non_last_ok = true,
.last_ok = true,
.changes_size = true,
@ -58,6 +64,7 @@ static const struct {
#ifdef HAVE_DECODER_X86
{
.id = LZMA_FILTER_X86,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -66,6 +73,7 @@ static const struct {
#if defined(HAVE_ENCODER_POWERPC) || defined(HAVE_DECODER_POWERPC)
{
.id = LZMA_FILTER_POWERPC,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -74,6 +82,7 @@ static const struct {
#ifdef HAVE_DECODER_IA64
{
.id = LZMA_FILTER_IA64,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -82,6 +91,7 @@ static const struct {
#if defined(HAVE_ENCODER_ARM) || defined(HAVE_DECODER_ARM)
{
.id = LZMA_FILTER_ARM,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -90,6 +100,7 @@ static const struct {
#if defined(HAVE_ENCODER_ARMTHUMB) || defined(HAVE_DECODER_ARMTHUMB)
{
.id = LZMA_FILTER_ARMTHUMB,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -98,6 +109,7 @@ static const struct {
#if defined(HAVE_ENCODER_SPARC) || defined(HAVE_DECODER_SPARC)
{
.id = LZMA_FILTER_SPARC,
.options_size = sizeof(lzma_options_bcj),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -106,6 +118,7 @@ static const struct {
#if defined(HAVE_ENCODER_DELTA) || defined(HAVE_DECODER_DELTA)
{
.id = LZMA_FILTER_DELTA,
.options_size = sizeof(lzma_options_delta),
.non_last_ok = true,
.last_ok = false,
.changes_size = false,
@ -117,6 +130,75 @@ static const struct {
};
extern LZMA_API(lzma_ret)
lzma_filters_dup(const lzma_filter *src, lzma_filter *dest,
lzma_allocator *allocator)
{
if (src == NULL || dest == NULL)
return LZMA_PROG_ERROR;
lzma_ret ret;
size_t i;
for (i = 0; src[i].id != LZMA_VLI_UNKNOWN; ++i) {
// There must be a maximum of four filters plus
// the array terminator.
if (i == LZMA_FILTERS_MAX) {
ret = LZMA_OPTIONS_ERROR;
goto error;
}
dest[i].id = src[i].id;
if (src[i].options == NULL) {
dest[i].options = NULL;
} else {
// See if the filter is supported only when the
// options is not NULL. This might be convenient
// sometimes if the app is actually copying only
// a partial filter chain with a place holder ID.
//
// When options is not NULL, the Filter ID must be
// supported by us, because otherwise we don't know
// how big the options are.
size_t j;
for (j = 0; src[i].id != features[j].id; ++j) {
if (features[j].id == LZMA_VLI_UNKNOWN) {
ret = LZMA_OPTIONS_ERROR;
goto error;
}
}
// Allocate and copy the options.
dest[i].options = lzma_alloc(features[j].options_size,
allocator);
if (dest[i].options == NULL) {
ret = LZMA_MEM_ERROR;
goto error;
}
memcpy(dest[i].options, src[i].options,
features[j].options_size);
}
}
// Terminate the filter array.
assert(i <= LZMA_FILTERS_MAX + 1);
dest[i].id = LZMA_VLI_UNKNOWN;
dest[i].options = NULL;
return LZMA_OK;
error:
// Free the options which we have already allocated.
while (i-- > 0) {
lzma_free(dest[i].options, allocator);
dest[i].options = NULL;
}
return ret;
}
static lzma_ret
validate_chain(const lzma_filter *filters, size_t *count)
{