The maximum size of a single Block is limited by the maximum size of a Stream, which in theory is 2^63 - 3 bytes (i.e. LZMA_VLI_MAX - 3). While the size is really big and no one should hit it in practice, we take it into account in some places anyway to catch some errors e.g. if application passes insanely big value to some function.

We could take into account the headers etc. to determine the exact maximum size of the Compressed Data field, but the complexity would give us nothing useful. Instead, limit the size of Compressed Data so that even with biggest possible Block Header and Check fields the total encoded size of the Block stays as a valid VLI. This doesn't guarantee that the size of the Stream doesn't grow too big, but that problem is taken care outside the Block handling code.

~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of the Compressed Data field, it will still stay in the proper limit.

This constant is in this file because it is needed in both block_encoder.c and block_buffer_encoder.c.

Definition at line 40 of file block_encoder.h.

Function Documentation

◆ lzma_block_encoder_init()

lzma_ret lzma_block_encoder_init	(	lzma_next_coder *	next,
		const lzma_allocator *	allocator,
		lzma_block *	block
	)

Definition at line 164 of file block_encoder.c.

 {
     lzma_next_coder_init(&lzma_block_encoder_init, next, allocator);
  
     if (block == NULL)
         return LZMA_PROG_ERROR;
  
     // The contents of the structure may depend on the version so
     // check the version first.
     if (block->version > 1)
         return LZMA_OPTIONS_ERROR;
  
     // If the Check ID is not supported, we cannot calculate the check and
     // thus not create a proper Block.
     if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
         return LZMA_PROG_ERROR;
  
     if (!lzma_check_is_supported(block->check))
         return LZMA_UNSUPPORTED_CHECK;
  
     // Allocate and initialize *next->coder if needed.
     lzma_block_coder *coder = next->coder;
     if (coder == NULL) {
         coder = lzma_alloc(sizeof(lzma_block_coder), allocator);
         if (coder == NULL)
             return LZMA_MEM_ERROR;
  
         next->coder = coder;
         next->code = &block_encode;
         next->end = &block_encoder_end;
         next->update = &block_encoder_update;
         coder->next = LZMA_NEXT_CODER_INIT;
     }
  
     // Basic initializations
     coder->sequence = SEQ_CODE;
     coder->block = block;
     coder->compressed_size = 0;
     coder->uncompressed_size = 0;
     coder->pos = 0;
  
     // Initialize the check
     lzma_check_init(&coder->check, block->check);
  
     // Initialize the requested filters.
     return lzma_raw_encoder_init(&coder->next, allocator, block->filters);
 }

References allocator, lzma_block_coder::block, block_encode(), block_encoder_end(), block_encoder_update(), lzma_block::check, lzma_block_coder::check, lzma_next_coder_s::code, lzma_next_coder_s::coder, lzma_block_coder::compressed_size, lzma_next_coder_s::end, lzma_block::filters, lzma_alloc(), LZMA_CHECK_ID_MAX, lzma_check_init(), LZMA_MEM_ERROR, LZMA_NEXT_CODER_INIT, lzma_next_coder_init, LZMA_OPTIONS_ERROR, LZMA_PROG_ERROR, lzma_raw_encoder_init(), LZMA_UNSUPPORTED_CHECK, lzma_block_coder::next, NULL, lzma_block_coder::pos, lzma_block_coder::sequence, lzma_block_coder::uncompressed_size, lzma_next_coder_s::update, and lzma_block::version.

Referenced by block_encoder_init(), LZMA_API(), and worker_encode().

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ COMPRESSED_SIZE_MAX

Function Documentation

◆ lzma_block_encoder_init()