liblzma: Add new API function lzma_filters_free().

This is small but convenient and should have been added
a long time ago.
This commit is contained in:
Lasse Collin 2022-11-24 01:02:50 +02:00
parent ae1f8a723d
commit d090164517
4 changed files with 49 additions and 0 deletions

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@ -124,6 +124,27 @@ extern LZMA_API(lzma_ret) lzma_filters_copy(
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Free the options in the array of lzma_filter structures
*
* This frees the filter chain options. The filters array itself is not freed.
*
* The filters array must have at most LZMA_FILTERS_MAX + 1 elements
* including the terminating element which must have .id = LZMA_VLI_UNKNOWN.
* For all elements before the terminating element:
* - options will be freed using the given lzma_allocator or,
* if allocator is NULL, using free().
* - options will be set to NULL.
* - id will be set to LZMA_VLI_UNKNOWN.
*
* If filters is NULL, this does nothing but remember that this never frees
* the filters array itself.
*/
extern LZMA_API(void) lzma_filters_free(
lzma_filter *filters, const lzma_allocator *allocator)
lzma_nothrow;
/**
* \brief Calculate approximate memory requirements for raw encoder
*

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@ -205,6 +205,32 @@ error:
}
extern LZMA_API(void)
lzma_filters_free(lzma_filter *filters, const lzma_allocator *allocator)
{
if (filters == NULL)
return;
for (size_t i = 0; filters[i].id != LZMA_VLI_UNKNOWN; ++i) {
if (i == LZMA_FILTERS_MAX) {
// The API says that LZMA_FILTERS_MAX + 1 is the
// maximum allowed size including the terminating
// element. Thus, we should never get here but in
// case there is a bug and we do anyway, don't go
// past the (probable) end of the array.
assert(0);
break;
}
lzma_free(filters[i].options, allocator);
filters[i].options = NULL;
filters[i].id = LZMA_VLI_UNKNOWN;
}
return;
}
static lzma_ret
validate_chain(const lzma_filter *filters, size_t *count)
{

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@ -114,4 +114,5 @@ global:
lzma_file_info_decoder;
lzma_stream_decoder_mt;
lzma_lzip_decoder;
lzma_filters_free;
} XZ_5.2;

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@ -129,4 +129,5 @@ global:
lzma_file_info_decoder;
lzma_stream_decoder_mt;
lzma_lzip_decoder;
lzma_filters_free;
} XZ_5.2;