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authorDenys Vlasenko <vda.linux@googlemail.com>2010-06-20 02:40:56 +0200
committerDenys Vlasenko <vda.linux@googlemail.com>2010-06-20 02:40:56 +0200
commitba73cfd28464f9ef926dfd27e264215d4c4f8b1f (patch)
tree1388876b477579cb6f43b4eb12b258b61bc8f010 /archival/libunarchive/unxz
parent91d7ee31f766a13595c1042d375f8374f2c3675f (diff)
downloadbusybox-ba73cfd28464f9ef926dfd27e264215d4c4f8b1f.tar.gz
unxz: update from XZ embedded git
function old new delta rc_reset - 21 +21 unpack_xz_stream 2342 2357 +15 lzma_reset 102 64 -38 lzma_len 506 443 -63 xz_dec_lzma2_run 1438 1374 -64 xz_dec_reset 73 - -73 lzma_main 2517 2183 -334 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 1/4 up/down: 36/-572) Total: -536 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'archival/libunarchive/unxz')
-rw-r--r--archival/libunarchive/unxz/xz.h139
-rw-r--r--archival/libunarchive/unxz/xz_dec_lzma2.c200
-rw-r--r--archival/libunarchive/unxz/xz_dec_stream.c17
-rw-r--r--archival/libunarchive/unxz/xz_private.h41
4 files changed, 253 insertions, 144 deletions
diff --git a/archival/libunarchive/unxz/xz.h b/archival/libunarchive/unxz/xz.h
index eb82706b9..c6c071c4a 100644
--- a/archival/libunarchive/unxz/xz.h
+++ b/archival/libunarchive/unxz/xz.h
@@ -30,9 +30,42 @@
#endif
/**
+ * enum xz_mode - Operation mode
+ *
+ * @XZ_SINGLE: Single-call mode. This uses less RAM than
+ * than multi-call modes, because the LZMA2
+ * dictionary doesn't need to be allocated as
+ * part of the decoder state. All required data
+ * structures are allocated at initialization,
+ * so xz_dec_run() cannot return XZ_MEM_ERROR.
+ * @XZ_PREALLOC: Multi-call mode with preallocated LZMA2
+ * dictionary buffer. All data structures are
+ * allocated at initialization, so xz_dec_run()
+ * cannot return XZ_MEM_ERROR.
+ * @XZ_DYNALLOC: Multi-call mode. The LZMA2 dictionary is
+ * allocated once the required size has been
+ * parsed from the stream headers. If the
+ * allocation fails, xz_dec_run() will return
+ * XZ_MEM_ERROR.
+ *
+ * It is possible to enable support only for a subset of the above
+ * modes at compile time by defining XZ_DEC_SINGLE, XZ_DEC_PREALLOC,
+ * or XZ_DEC_DYNALLOC. The xz_dec kernel module is always compiled
+ * with support for all operation modes, but the preboot code may
+ * be built with fewer features to minimize code size.
+ */
+enum xz_mode {
+ XZ_SINGLE,
+ XZ_PREALLOC,
+ XZ_DYNALLOC
+};
+
+/**
* enum xz_ret - Return codes
* @XZ_OK: Everything is OK so far. More input or more
- * output space is required to continue.
+ * output space is required to continue. This
+ * return code is possible only in multi-call mode
+ * (XZ_PREALLOC or XZ_DYNALLOC).
* @XZ_STREAM_END: Operation finished successfully.
* @XZ_UNSUPPORTED_CHECK: Integrity check type is not supported. Decoding
* is still possible in multi-call mode by simply
@@ -42,8 +75,17 @@
* which is not used in the kernel. Unsupported
* check types return XZ_OPTIONS_ERROR if
* XZ_DEC_ANY_CHECK was not defined at build time.
- * @XZ_MEMLIMIT_ERROR: Not enough memory was preallocated at decoder
- * initialization time.
+ * @XZ_MEM_ERROR: Allocating memory failed. This return code is
+ * possible only if the decoder was initialized
+ * with XZ_DYNALLOC. The amount of memory that was
+ * tried to be allocated was no more than the
+ * dict_max argument given to xz_dec_init().
+ * @XZ_MEMLIMIT_ERROR: A bigger LZMA2 dictionary would be needed than
+ * allowed by the dict_max argument given to
+ * xz_dec_init(). This return value is possible
+ * only in multi-call mode (XZ_PREALLOC or
+ * XZ_DYNALLOC); the single-call mode (XZ_SINGLE)
+ * ignores the dict_max argument.
* @XZ_FORMAT_ERROR: File format was not recognized (wrong magic
* bytes).
* @XZ_OPTIONS_ERROR: This implementation doesn't support the requested
@@ -72,6 +114,7 @@ enum xz_ret {
XZ_OK,
XZ_STREAM_END,
XZ_UNSUPPORTED_CHECK,
+ XZ_MEM_ERROR,
XZ_MEMLIMIT_ERROR,
XZ_FORMAT_ERROR,
XZ_OPTIONS_ERROR,
@@ -112,61 +155,67 @@ struct xz_dec;
/**
* xz_dec_init() - Allocate and initialize a XZ decoder state
+ * @mode: Operation mode
* @dict_max: Maximum size of the LZMA2 dictionary (history buffer) for
- * multi-call decoding, or special value of zero to indicate
- * single-call decoding mode.
- *
- * If dict_max > 0, the decoder is initialized to work in multi-call mode.
- * dict_max number of bytes of memory is preallocated for the LZMA2
- * dictionary. This way there is no risk that xz_dec_run() could run out
- * of memory, since xz_dec_run() will never allocate any memory. Instead,
- * if the preallocated dictionary is too small for decoding the given input
- * stream, xz_dec_run() will return XZ_MEMLIMIT_ERROR. Thus, it is important
- * to know what kind of data will be decoded to avoid allocating excessive
- * amount of memory for the dictionary.
- *
- * LZMA2 dictionary is always 2^n bytes or 2^n + 2^(n-1) bytes (the latter
- * sizes are less common in practice). In the kernel, dictionary sizes of
- * 64 KiB, 128 KiB, 256 KiB, 512 KiB, and 1 MiB are probably the only
- * reasonable values.
- *
- * If dict_max == 0, the decoder is initialized to work in single-call mode.
- * In single-call mode, xz_dec_run() decodes the whole stream at once. The
- * caller must provide enough output space or the decoding will fail. The
- * output space is used as the dictionary buffer, which is why there is
- * no need to allocate the dictionary as part of the decoder's internal
- * state.
+ * multi-call decoding. This is ignored in single-call mode
+ * (mode == XZ_SINGLE). LZMA2 dictionary is always 2^n bytes
+ * or 2^n + 2^(n-1) bytes (the latter sizes are less common
+ * in practice), so other values for dict_max don't make sense.
+ * In the kernel, dictionary sizes of 64 KiB, 128 KiB, 256 KiB,
+ * 512 KiB, and 1 MiB are probably the only reasonable values,
+ * except for kernel and initramfs images where a bigger
+ * dictionary can be fine and useful.
+ *
+ * Single-call mode (XZ_SINGLE): xz_dec_run() decodes the whole stream at
+ * once. The caller must provide enough output space or the decoding will
+ * fail. The output space is used as the dictionary buffer, which is why
+ * there is no need to allocate the dictionary as part of the decoder's
+ * internal state.
*
* Because the output buffer is used as the workspace, streams encoded using
- * a big dictionary are not a problem in single-call. It is enough that the
- * output buffer is big enough to hold the actual uncompressed data; it
+ * a big dictionary are not a problem in single-call mode. It is enough that
+ * the output buffer is big enough to hold the actual uncompressed data; it
* can be smaller than the dictionary size stored in the stream headers.
*
+ * Multi-call mode with preallocated dictionary (XZ_PREALLOC): dict_max bytes
+ * of memory is preallocated for the LZMA2 dictionary. This way there is no
+ * risk that xz_dec_run() could run out of memory, since xz_dec_run() will
+ * never allocate any memory. Instead, if the preallocated dictionary is too
+ * small for decoding the given input stream, xz_dec_run() will return
+ * XZ_MEMLIMIT_ERROR. Thus, it is important to know what kind of data will be
+ * decoded to avoid allocating excessive amount of memory for the dictionary.
+ *
+ * Multi-call mode with dynamically allocated dictionary (XZ_DYNALLOC):
+ * dict_max specifies the maximum allowed dictionary size that xz_dec_run()
+ * may allocate once it has parsed the dictionary size from the stream
+ * headers. This way excessive allocations can be avoided while still
+ * limiting the maximum memory usage to a sane value to prevent running the
+ * system out of memory when decompressing streams from untrusted sources.
+ *
* On success, xz_dec_init() returns a pointer to struct xz_dec, which is
- * ready to be used with xz_dec_run(). On error, xz_dec_init() returns NULL.
+ * ready to be used with xz_dec_run(). If memory allocation fails,
+ * xz_dec_init() returns NULL.
*/
-XZ_EXTERN struct xz_dec * XZ_FUNC xz_dec_init(uint32_t dict_max);
+XZ_EXTERN struct xz_dec * XZ_FUNC xz_dec_init(
+ enum xz_mode mode, uint32_t dict_max);
/**
* xz_dec_run() - Run the XZ decoder
* @s: Decoder state allocated using xz_dec_init()
* @b: Input and output buffers
*
- * In multi-call mode, this function may return any of the values listed in
- * enum xz_ret.
- *
- * In single-call mode, this function never returns XZ_OK. If an error occurs
- * in single-call mode (return value is not XZ_STREAM_END), b->in_pos and
- * b->out_pos are not modified, and the contents of the output buffer from
- * b->out[b->out_pos] onward are undefined.
- *
- * NOTE: In single-call mode, the contents of the output buffer are undefined
- * also after XZ_BUF_ERROR. This is because with some filter chains, there
- * may be a second pass over the output buffer, and this pass cannot be
- * properly done if the output buffer is truncated. Thus, you cannot give
- * the single-call decoder a too small buffer and then expect to get that
- * amount valid data from the beginning of the stream. You must use the
- * multi-call decoder if you don't want to uncompress the whole stream.
+ * The possible return values depend on build options and operation mode.
+ * See enum xz_ret for details.
+ *
+ * NOTE: If an error occurs in single-call mode (return value is not
+ * XZ_STREAM_END), b->in_pos and b->out_pos are not modified, and the
+ * contents of the output buffer from b->out[b->out_pos] onward are
+ * undefined. This is true even after XZ_BUF_ERROR, because with some filter
+ * chains, there may be a second pass over the output buffer, and this pass
+ * cannot be properly done if the output buffer is truncated. Thus, you
+ * cannot give the single-call decoder a too small buffer and then expect to
+ * get that amount valid data from the beginning of the stream. You must use
+ * the multi-call decoder if you don't want to uncompress the whole stream.
*/
XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_run(struct xz_dec *s, struct xz_buf *b);
diff --git a/archival/libunarchive/unxz/xz_dec_lzma2.c b/archival/libunarchive/unxz/xz_dec_lzma2.c
index 37de6fc32..da71cb4d4 100644
--- a/archival/libunarchive/unxz/xz_dec_lzma2.c
+++ b/archival/libunarchive/unxz/xz_dec_lzma2.c
@@ -34,7 +34,8 @@
*
* In multi-call mode, also these are true:
* end == size
- * size <= allocated
+ * size <= size_max
+ * allocated <= size
*
* Most of these variables are size_t to support single-call mode,
* in which the dictionary variables address the actual output
@@ -74,11 +75,20 @@ struct dictionary {
uint32_t size;
/*
- * Amount of memory allocated for the dictionary. A special
- * value of zero indicates that we are in single-call mode,
- * where the output buffer works as the dictionary.
+ * Maximum allowed dictionary size in multi-call mode.
+ * This is ignored in single-call mode.
+ */
+ uint32_t size_max;
+
+ /*
+ * Amount of memory currently allocated for the dictionary.
+ * This is used only with XZ_DYNALLOC. (With XZ_PREALLOC,
+ * size_max is always the same as the allocated size.)
*/
uint32_t allocated;
+
+ /* Operation mode */
+ enum xz_mode mode;
};
/* Range decoder */
@@ -120,31 +130,31 @@ struct lzma_len_dec {
};
struct lzma_dec {
- /*
- * LZMA properties or related bit masks (number of literal
- * context bits, a mask dervied from the number of literal
- * position bits, and a mask dervied from the number
- * position bits)
- */
- uint32_t lc;
- uint32_t literal_pos_mask; /* (1 << lp) - 1 */
- uint32_t pos_mask; /* (1 << pb) - 1 */
-
- /* Types of the most recently seen LZMA symbols */
- enum lzma_state state;
-
/* Distances of latest four matches */
uint32_t rep0;
uint32_t rep1;
uint32_t rep2;
uint32_t rep3;
+ /* Types of the most recently seen LZMA symbols */
+ enum lzma_state state;
+
/*
* Length of a match. This is updated so that dict_repeat can
* be called again to finish repeating the whole match.
*/
uint32_t len;
+ /*
+ * LZMA properties or related bit masks (number of literal
+ * context bits, a mask dervied from the number of literal
+ * position bits, and a mask dervied from the number
+ * position bits)
+ */
+ uint32_t lc;
+ uint32_t literal_pos_mask; /* (1 << lp) - 1 */
+ uint32_t pos_mask; /* (1 << pb) - 1 */
+
/* If 1, it's a match. Otherwise it's a single 8-bit literal. */
uint16_t is_match[STATES][POS_STATES_MAX];
@@ -201,49 +211,59 @@ struct lzma_dec {
uint16_t literal[LITERAL_CODERS_MAX][LITERAL_CODER_SIZE];
};
+struct lzma2_dec {
+ /* Position in xz_dec_lzma2_run(). */
+ enum lzma2_seq {
+ SEQ_CONTROL,
+ SEQ_UNCOMPRESSED_1,
+ SEQ_UNCOMPRESSED_2,
+ SEQ_COMPRESSED_0,
+ SEQ_COMPRESSED_1,
+ SEQ_PROPERTIES,
+ SEQ_LZMA_PREPARE,
+ SEQ_LZMA_RUN,
+ SEQ_COPY
+ } sequence;
+
+ /* Next position after decoding the compressed size of the chunk. */
+ enum lzma2_seq next_sequence;
+
+ /* Uncompressed size of LZMA chunk (2 MiB at maximum) */
+ uint32_t uncompressed;
+
+ /*
+ * Compressed size of LZMA chunk or compressed/uncompressed
+ * size of uncompressed chunk (64 KiB at maximum)
+ */
+ uint32_t compressed;
+
+ /*
+ * True if dictionary reset is needed. This is false before
+ * the first chunk (LZMA or uncompressed).
+ */
+ bool need_dict_reset;
+
+ /*
+ * True if new LZMA properties are needed. This is false
+ * before the first LZMA chunk.
+ */
+ bool need_props;
+};
+
struct xz_dec_lzma2 {
- /* LZMA2 */
- struct {
- /* Position in xz_dec_lzma2_run(). */
- enum lzma2_seq {
- SEQ_CONTROL,
- SEQ_UNCOMPRESSED_1,
- SEQ_UNCOMPRESSED_2,
- SEQ_COMPRESSED_0,
- SEQ_COMPRESSED_1,
- SEQ_PROPERTIES,
- SEQ_LZMA_PREPARE,
- SEQ_LZMA_RUN,
- SEQ_COPY
- } sequence;
-
- /*
- * Next position after decoding the compressed size of
- * the chunk.
- */
- enum lzma2_seq next_sequence;
-
- /* Uncompressed size of LZMA chunk (2 MiB at maximum) */
- uint32_t uncompressed;
-
- /*
- * Compressed size of LZMA chunk or compressed/uncompressed
- * size of uncompressed chunk (64 KiB at maximum)
- */
- uint32_t compressed;
-
- /*
- * True if dictionary reset is needed. This is false before
- * the first chunk (LZMA or uncompressed).
- */
- bool need_dict_reset;
-
- /*
- * True if new LZMA properties are needed. This is false
- * before the first LZMA chunk.
- */
- bool need_props;
- } lzma2;
+ /*
+ * The order below is important on x86 to reduce code size and
+ * it shouldn't hurt on other platforms. Everything up to and
+ * including lzma.pos_mask are in the first 128 bytes on x86-32,
+ * which allows using smaller instructions to access those
+ * variables. On x86-64, fewer variables fit into the first 128
+ * bytes, but this is still the best order without sacrificing
+ * the readability by splitting the structures.
+ */
+ struct rc_dec rc;
+ struct dictionary dict;
+ struct lzma2_dec lzma2;
+ struct lzma_dec lzma;
/*
* Temporary buffer which holds small number of input bytes between
@@ -253,10 +273,6 @@ struct xz_dec_lzma2 {
uint32_t size;
uint8_t buf[3 * LZMA_IN_REQUIRED];
} temp;
-
- struct dictionary dict;
- struct rc_dec rc;
- struct lzma_dec lzma;
};
/**************
@@ -269,7 +285,7 @@ struct xz_dec_lzma2 {
*/
static void XZ_FUNC dict_reset(struct dictionary *dict, struct xz_buf *b)
{
- if (dict->allocated == 0) {
+ if (DEC_IS_SINGLE(dict->mode)) {
dict->buf = b->out + b->out_pos;
dict->end = b->out_size - b->out_pos;
}
@@ -379,7 +395,7 @@ static void XZ_FUNC dict_uncompressed(
if (dict->full < dict->pos)
dict->full = dict->pos;
- if (dict->allocated != 0) {
+ if (DEC_IS_MULTI(dict->mode)) {
if (dict->pos == dict->end)
dict->pos = 0;
@@ -404,7 +420,7 @@ static uint32_t XZ_FUNC dict_flush(struct dictionary *dict, struct xz_buf *b)
{
size_t copy_size = dict->pos - dict->start;
- if (dict->allocated != 0) {
+ if (DEC_IS_MULTI(dict->mode)) {
if (dict->pos == dict->end)
dict->pos = 0;
@@ -422,7 +438,7 @@ static uint32_t XZ_FUNC dict_flush(struct dictionary *dict, struct xz_buf *b)
*****************/
/* Reset the range decoder. */
-static __always_inline void XZ_FUNC rc_reset(struct rc_dec *rc)
+static void XZ_FUNC rc_reset(struct rc_dec *rc)
{
rc->range = (uint32_t)-1;
rc->code = 0;
@@ -1088,28 +1104,27 @@ XZ_EXTERN NOINLINE enum xz_ret XZ_FUNC xz_dec_lzma2_run(
return XZ_OK;
}
-XZ_EXTERN struct xz_dec_lzma2 * XZ_FUNC xz_dec_lzma2_create(uint32_t dict_max)
+XZ_EXTERN struct xz_dec_lzma2 * XZ_FUNC xz_dec_lzma2_create(
+ enum xz_mode mode, uint32_t dict_max)
{
- struct xz_dec_lzma2 *s;
-
- /* Maximum supported dictionary by this implementation is 3 GiB. */
- if (dict_max > ((uint32_t)3 << 30))
- return NULL;
-
- s = kmalloc(sizeof(*s), GFP_KERNEL);
+ struct xz_dec_lzma2 *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s == NULL)
return NULL;
- if (dict_max > 0) {
+ s->dict.mode = mode;
+ s->dict.size_max = dict_max;
+
+ if (DEC_IS_PREALLOC(mode)) {
s->dict.buf = vmalloc(dict_max);
if (s->dict.buf == NULL) {
kfree(s);
return NULL;
}
+ } else if (DEC_IS_DYNALLOC(mode)) {
+ s->dict.buf = NULL;
+ s->dict.allocated = 0;
}
- s->dict.allocated = dict_max;
-
return s;
}
@@ -1123,18 +1138,23 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_lzma2_reset(
s->dict.size = 2 + (props & 1);
s->dict.size <<= (props >> 1) + 11;
- if (s->dict.allocated > 0 && s->dict.allocated < s->dict.size) {
-#ifdef XZ_REALLOC_DICT_BUF
- s->dict.buf = XZ_REALLOC_DICT_BUF(s->dict.buf, s->dict.size);
- if (!s->dict.buf)
- return XZ_MEMLIMIT_ERROR;
- s->dict.allocated = s->dict.size;
-#else
- return XZ_MEMLIMIT_ERROR;
-#endif
- }
+ if (DEC_IS_MULTI(s->dict.mode)) {
+ if (s->dict.size > s->dict.size_max)
+ return XZ_MEMLIMIT_ERROR;
- s->dict.end = s->dict.size;
+ s->dict.end = s->dict.size;
+
+ if (DEC_IS_DYNALLOC(s->dict.mode)) {
+ if (s->dict.allocated < s->dict.size) {
+ vfree(s->dict.buf);
+ s->dict.buf = vmalloc(s->dict.size);
+ if (s->dict.buf == NULL) {
+ s->dict.allocated = 0;
+ return XZ_MEM_ERROR;
+ }
+ }
+ }
+ }
s->lzma.len = 0;
@@ -1148,7 +1168,7 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_lzma2_reset(
XZ_EXTERN void XZ_FUNC xz_dec_lzma2_end(struct xz_dec_lzma2 *s)
{
- if (s->dict.allocated > 0)
+ if (DEC_IS_MULTI(s->dict.mode))
vfree(s->dict.buf);
kfree(s);
diff --git a/archival/libunarchive/unxz/xz_dec_stream.c b/archival/libunarchive/unxz/xz_dec_stream.c
index 21db283fb..bdcbf1ba3 100644
--- a/archival/libunarchive/unxz/xz_dec_stream.c
+++ b/archival/libunarchive/unxz/xz_dec_stream.c
@@ -48,8 +48,8 @@ struct xz_dec {
/* Type of the integrity check calculated from uncompressed data */
enum xz_check check_type;
- /* True if we are operating in single-call mode. */
- bool single_call;
+ /* Operation mode */
+ enum xz_mode mode;
/*
* True if the next call to xz_dec_run() is allowed to return
@@ -737,14 +737,14 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_run(struct xz_dec *s, struct xz_buf *b)
size_t out_start;
enum xz_ret ret;
- if (s->single_call)
+ if (DEC_IS_SINGLE(s->mode))
xz_dec_reset(s);
in_start = b->in_pos;
out_start = b->out_pos;
ret = dec_main(s, b);
- if (s->single_call) {
+ if (DEC_IS_SINGLE(s->mode)) {
if (ret == XZ_OK)
ret = b->in_pos == b->in_size
? XZ_DATA_ERROR : XZ_BUF_ERROR;
@@ -767,21 +767,22 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_run(struct xz_dec *s, struct xz_buf *b)
return ret;
}
-XZ_EXTERN struct xz_dec * XZ_FUNC xz_dec_init(uint32_t dict_max)
+XZ_EXTERN struct xz_dec * XZ_FUNC xz_dec_init(
+ enum xz_mode mode, uint32_t dict_max)
{
struct xz_dec *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s == NULL)
return NULL;
- s->single_call = dict_max == 0;
+ s->mode = mode;
#ifdef XZ_DEC_BCJ
- s->bcj = xz_dec_bcj_create(s->single_call);
+ s->bcj = xz_dec_bcj_create(DEC_IS_SINGLE(mode));
if (s->bcj == NULL)
goto error_bcj;
#endif
- s->lzma2 = xz_dec_lzma2_create(dict_max);
+ s->lzma2 = xz_dec_lzma2_create(mode, dict_max);
if (s->lzma2 == NULL)
goto error_lzma2;
diff --git a/archival/libunarchive/unxz/xz_private.h b/archival/libunarchive/unxz/xz_private.h
index f4e0b4010..145649a83 100644
--- a/archival/libunarchive/unxz/xz_private.h
+++ b/archival/libunarchive/unxz/xz_private.h
@@ -53,6 +53,45 @@
# include "xz_config.h"
#endif
+/* If no specific decoding mode is requested, enable support for all modes. */
+#if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
+ && !defined(XZ_DEC_DYNALLOC)
+# define XZ_DEC_SINGLE
+# define XZ_DEC_PREALLOC
+# define XZ_DEC_DYNALLOC
+#endif
+
+/*
+ * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
+ * of the supported modes are enabled, these macros will evaluate to true or
+ * false at compile time and thus allow the compiler to omit unneeded code.
+ */
+#ifdef XZ_DEC_SINGLE
+# define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
+#else
+# define DEC_IS_SINGLE(mode) (false)
+#endif
+
+#ifdef XZ_DEC_PREALLOC
+# define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
+#else
+# define DEC_IS_PREALLOC(mode) (false)
+#endif
+
+#ifdef XZ_DEC_DYNALLOC
+# define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
+#else
+# define DEC_IS_DYNALLOC(mode) (false)
+#endif
+
+#if !defined(XZ_DEC_SINGLE)
+# define DEC_IS_MULTI(mode) (true)
+#elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
+# define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
+#else
+# define DEC_IS_MULTI(mode) (false)
+#endif
+
/*
* If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
* XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
@@ -71,7 +110,7 @@
* before calling xz_dec_lzma2_run().
*/
XZ_EXTERN struct xz_dec_lzma2 * XZ_FUNC xz_dec_lzma2_create(
- uint32_t dict_max);
+ enum xz_mode mode, uint32_t dict_max);
/*
* Decode the LZMA2 properties (one byte) and reset the decoder. Return