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libarchive: add capability to unpack to mem.buffer

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The performance and number of processes for a "depmod -a" with gzipped
modules was abysmal. This patch adds a code path without fork,
benefiting all users of xmalloc_open_zipped_read_close.

"modinfo radeon.ko.gz", a single-file reader, got 30% faster.
"depmod -a", which used to fork over 800 times, got 20% faster.

Heavily based on a patch by Lauri Kasanen <curaga@operamail.com>

function                                             old     new   delta
setup_transformer_on_fd                                -     159    +159
transformer_write                                      -     122    +122
fork_transformer                                       -     112    +112
xmalloc_open_zipped_read_close                        63     118     +55
read_bunzip                                         1866    1896     +30
xtransformer_write                                     -      19     +19
unzip_main                                          2449    2462     +13
bbunpack                                             755     766     +11
unpack_lzma_stream                                  2717    2723      +6
unpack_xz_stream                                    2393    2397      +4
unpack_Z_stream                                     1173    1175      +2
inflate_unzip                                        111     105      -6
check_signature16                                     70      63      -7
unpack_bz2_stream                                    359     349     -10
unpack_unxz                                           12       -     -12
unpack_unlzma                                         12       -     -12
unpack_uncompress                                     12       -     -12
unpack_gunzip                                         12       -     -12
unpack_bunzip2                                        12       -     -12
open_transformer                                     106      92     -14
inflate_unzip_internal                              1945    1916     -29
unpack_gz_stream                                     693     655     -38
open_zipped                                           89      47     -42
setup_unzip_on_fd                                    142      53     -89
------------------------------------------------------------------------------
(add/remove: 4/5 grow/shrink: 7/8 up/down: 533/-295)          Total: 238 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2014-12-07 00:44:00 +01:00
parent e7800f351a
commit b4c11c1397
14 changed files with 243 additions and 127 deletions
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12
archival/libarchive/decompress_unlzma.c
View File

@@ -206,7 +206,7 @@ enum {
IF_DESKTOP(long long) int FAST_FUNC
unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst_fd)
unpack_lzma_stream(transformer_state_t *xstate)
{
IF_DESKTOP(long long total_written = 0;)
lzma_header_t header;
@@ -223,7 +223,7 @@ unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst
int state = 0;
uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
if (full_read(src_fd, &header, sizeof(header)) != sizeof(header)
if (full_read(xstate->src_fd, &header, sizeof(header)) != sizeof(header)
|| header.pos >= (9 * 5 * 5)
) {
bb_error_msg("bad lzma header");
@@ -258,7 +258,7 @@ unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
}
rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */
rc = rc_init(xstate->src_fd); /*, RC_BUFFER_SIZE); */
while (global_pos + buffer_pos < header.dst_size) {
int pos_state = (buffer_pos + global_pos) & pos_state_mask;
@@ -306,7 +306,7 @@ unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst
if (buffer_pos == header.dict_size) {
buffer_pos = 0;
global_pos += header.dict_size;
if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
if (transformer_write(xstate, buffer, header.dict_size) != (ssize_t)header.dict_size)
goto bad;
IF_DESKTOP(total_written += header.dict_size;)
}
@@ -440,7 +440,7 @@ unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst
if (buffer_pos == header.dict_size) {
buffer_pos = 0;
global_pos += header.dict_size;
if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
if (transformer_write(xstate, buffer, header.dict_size) != (ssize_t)header.dict_size)
goto bad;
IF_DESKTOP(total_written += header.dict_size;)
}
@@ -455,7 +455,7 @@ unpack_lzma_stream(transformer_state_t *xstate UNUSED_PARAM, int src_fd, int dst
{
IF_NOT_DESKTOP(int total_written = 0; /* success */)
IF_DESKTOP(total_written += buffer_pos;)
if (full_write(dst_fd, buffer, buffer_pos) != (ssize_t)buffer_pos) {
if (transformer_write(xstate, buffer, buffer_pos) != (ssize_t)buffer_pos) {
bad:
total_written = -1; /* failure */
}