///////////////////////////////////////////////////////////////////////////////
//
/// \file common.h
/// \brief Definitions common to the whole liblzma library
//
// Copyright (C) 2007-2008 Lasse Collin
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef LZMA_COMMON_H
#define LZMA_COMMON_H
#include "../../common/sysdefs.h"
#include "../../common/integer.h"
// Don't use ifdef...
#if HAVE_VISIBILITY
# define LZMA_API __attribute__((__visibility__("default")))
#else
# define LZMA_API
#endif
// These allow helping the compiler in some often-executed branches, whose
// result is almost always the same.
#ifdef __GNUC__
# define likely(expr) __builtin_expect(expr, true)
# define unlikely(expr) __builtin_expect(expr, false)
#else
# define likely(expr) (expr)
# define unlikely(expr) (expr)
#endif
/// Size of temporary buffers needed in some filters
#define LZMA_BUFFER_SIZE 4096
/// Start of internal Filter ID space. These IDs must never be used
/// in Streams.
#define LZMA_FILTER_RESERVED_START (LZMA_VLI_C(1) << 62)
/// Internal helper filter used by Subblock decoder. It is mapped to an
/// otherwise invalid Filter ID, which is impossible to get from any input
/// file (even if malicious file).
#define LZMA_FILTER_SUBBLOCK_HELPER (LZMA_FILTER_RESERVED_START + 1)
/// Supported flags that can be passed to lzma_stream_decoder()
/// or lzma_auto_decoder().
#define LZMA_SUPPORTED_FLAGS \
(LZMA_WARN_NO_CHECK \
| LZMA_WARN_UNSUPPORTED_CHECK \
| LZMA_TELL_CHECK \
| LZMA_CONCATENATED)
///////////
// Types //
///////////
/// Type of encoder/decoder specific data; the actual structure is defined
/// differently in different coders.
typedef struct lzma_coder_s lzma_coder;
typedef struct lzma_next_coder_s lzma_next_coder;
typedef struct lzma_filter_info_s lzma_filter_info;
/// Type of a function used to initialize a filter encoder or decoder
typedef lzma_ret (*lzma_init_function)(
lzma_next_coder *next, lzma_allocator *allocator,
const lzma_filter_info *filters);
/// Type of a function to do some kind of coding work (filters, Stream,
/// Block encoders/decoders etc.). Some special coders use don't use both
/// input and output buffers, but for simplicity they still use this same
/// function prototype.
typedef lzma_ret (*lzma_code_function)(
lzma_coder *coder, 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);
/// Type of a function to free the memory allocated for the coder
typedef void (*lzma_end_function)(
lzma_coder *coder, lzma_allocator *allocator);
/// Raw coder validates and converts an array of lzma_filter structures to
/// an array of lzma_filter_info structures. This array is used with
/// lzma_next_filter_init to initialize the filter chain.
struct lzma_filter_info_s {
/// Pointer to function used to initialize the filter.
/// This is NULL to indicate end of array.
lzma_init_function init;
/// Pointer to filter's options structure
void *options;
};
/// Hold data and function pointers of the next filter in the chain.
struct lzma_next_coder_s {
/// Pointer to coder-specific data
lzma_coder *coder;
/// "Pointer" to init function. This is never called here.
/// We need only to detect if we are initializing a coder
/// that was allocated earlier. See lzma_next_coder_init and
/// lzma_next_strm_init macros in this file.
uintptr_t init;
/// Pointer to function to do the actual coding
lzma_code_function code;
/// Pointer to function to free lzma_next_coder.coder. This can
/// be NULL; in that case, lzma_free is called to free
/// lzma_next_coder.coder.
lzma_end_function end;
/// Pointer to function to return the type of the integrity check.
/// Most coders won't support this.
lzma_check (*see_check)(const lzma_coder *coder);
// uint64_t (*memconfig)(
// lzma_coder *coder, uint64_t memlimit, bool change);
};
/// Macro to initialize lzma_next_coder structure
#define LZMA_NEXT_CODER_INIT \
(lzma_next_coder){ \
.coder = NULL, \
.init = (uintptr_t)(NULL), \
.code = NULL, \
.end = NULL, \
.see_check = NULL, \
}
/// Internal data for lzma_strm_init, lzma_code, and lzma_end. A pointer to
/// this is stored in lzma_stream.
struct lzma_internal_s {
/// The actual coder that should do something useful
lzma_next_coder next;
/// Track the state of the coder. This is used to validate arguments
/// so that the actual coders can rely on e.g. that LZMA_SYNC_FLUSH
/// is used on every call to lzma_code until next.code has returned
/// LZMA_STREAM_END.
enum {
ISEQ_RUN,
ISEQ_SYNC_FLUSH,
ISEQ_FULL_FLUSH,
ISEQ_FINISH,
ISEQ_END,
ISEQ_ERROR,
} sequence;
/// A copy of lzma_stream avail_in. This is used to verify that the
/// amount of input doesn't change once e.g. LZMA_FINISH has been
/// used.
size_t avail_in;
/// Indicates which lzma_action values are allowed by next.code.
bool supported_actions[4];
/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
/// made (no input consumed and no output produced by next.code).
bool allow_buf_error;
};
///////////////
// Functions //
///////////////
/// Allocates memory
extern void *lzma_alloc(size_t size, lzma_allocator *allocator)
lzma_attribute((malloc));
/// Frees memory
extern void lzma_free(void *ptr, lzma_allocator *allocator);
/// Allocates strm->internal if it is NULL, and initializes *strm and
/// strm->internal. This function is only called via lzma_next_strm_init macro.
extern lzma_ret lzma_strm_init(lzma_stream *strm);
/// Initializes the next filter in the chain, if any. This takes care of
/// freeing the memory of previously initialized filter if it is different
/// than the filter being initialized now. This way the actual filter
/// initialization functions don't need to use lzma_next_coder_init macro.
extern lzma_ret lzma_next_filter_init(lzma_next_coder *next,
lzma_allocator *allocator, const lzma_filter_info *filters);
/// Frees the memory allocated for next->coder either using next->end or,
/// if next->end is NULL, using lzma_free.
extern void lzma_next_end(lzma_next_coder *next, lzma_allocator *allocator);
/// Copy as much data as possible from in[] to out[] and update *in_pos
/// and *out_pos accordingly. Returns the number of bytes copied.
extern size_t lzma_bufcpy(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);
/// \brief Return if expression doesn't evaluate to LZMA_OK
///
/// There are several situations where we want to return immediatelly
/// with the value of expr if it isn't LZMA_OK. This macro shortens
/// the code a little.
#define return_if_error(expr) \
do { \
const lzma_ret ret_ = (expr); \
if (ret_ != LZMA_OK) \
return ret_; \
} while (0)
/// If next isn't already initialized, free the previous coder. Then mark
/// that next is _possibly_ initialized for the coder using this macro.
/// "Possibly" means that if e.g. allocation of next->coder fails, the
/// structure isn't actually initialized for this coder, but leaving
/// next->init to func is still OK.
#define lzma_next_coder_init(func, next, allocator) \
do { \
if ((uintptr_t)(&func) != (next)->init) \
lzma_next_end(next, allocator); \
(next)->init = (uintptr_t)(&func); \
} while (0)
/// Initializes lzma_strm and calls func() to initialize strm->internal->next.
/// (The function being called will use lzma_next_coder_init()). If
/// initialization fails, memory that wasn't freed by func() is freed
/// along strm->internal.
#define lzma_next_strm_init(func, strm, ...) \
do { \
return_if_error(lzma_strm_init(strm)); \
const lzma_ret ret_ = func(&(strm)->internal->next, \
(strm)->allocator, __VA_ARGS__); \
if (ret_ != LZMA_OK) { \
lzma_end(strm); \
return ret_; \
} \
} while (0)
#endif
