← Commit list

434f95960

Denys Vlasenko
Denys Vlasenko
2018-04-08
SUCCESS Duration: 142s

Subject

lzop: code shrink by using header_t matching on-disk layout

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

archival/lzop.c +154 -177
archival/lzop.c+154 -177
@@ -438,36 +438,33 @@ typedef struct chksum_t {
} chksum_t;
typedef struct header_t {
- unsigned version;
- unsigned lib_version;
- unsigned version_needed_to_extract;
- uint32_t flags;
- uint32_t mode;
- uint32_t mtime;
- uint32_t gmtdiff;
- uint32_t header_checksum;
-
- uint32_t extra_field_len;
- uint32_t extra_field_checksum;
-
- unsigned char method;
- unsigned char level;
-
- /* info */
- char name[255+1];
+ /* used to have auxiliary fields here */
+
+ /* Starting from here, the layout and endianness
+ * are exactly in on-disk format.
+ */
+ uint16_t version_be16;
+ uint16_t lib_version_be16;
+ uint16_t version_needed_to_extract_be16;
+ uint8_t method;
+ uint8_t level;
+ uint32_t flags32; /* be32 on disk, but we keep them in native order */
+ uint32_t mode_be32;
+ uint32_t mtime_be32;
+ uint32_t gmtdiff_be32;
+ char len_and_name[1+255+1];
} header_t;
struct globals {
/*const uint32_t *lzo_crc32_table;*/
- chksum_t chksum_in;
- chksum_t chksum_out;
+ chksum_t chksum;
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
-#define INIT_G() do { setup_common_bufsiz(); } while (0)
//#define G (*ptr_to_globals)
-//#define INIT_G() do {
-// SET_PTR_TO_GLOBALS(xzalloc(sizeof(G)));
-//} while (0)
+#define INIT_G() do { \
+ setup_common_bufsiz(); \
+ /*SET_PTR_TO_GLOBALS(xzalloc(sizeof(G)));*/ \
+} while (0)
/**********************************************************************/
@@ -548,24 +545,24 @@ lzo_crc32(uint32_t c, const uint8_t* buf, unsigned len)
}
/**********************************************************************/
-static void init_chksum(chksum_t *ct)
+static void init_chksum(void)
{
- ct->f_adler32 = ADLER32_INIT_VALUE;
- ct->f_crc32 = CRC32_INIT_VALUE;
+ G.chksum.f_adler32 = ADLER32_INIT_VALUE;
+ G.chksum.f_crc32 = CRC32_INIT_VALUE;
}
-static void add_bytes_to_chksum(chksum_t *ct, const void* buf, int cnt)
+static void add_bytes_to_chksum(const void* buf, int cnt)
{
/* We need to handle the two checksums at once, because at the
* beginning of the header, we don't know yet which one we'll
* eventually need */
- ct->f_adler32 = lzo_adler32(ct->f_adler32, (const uint8_t*)buf, cnt);
- ct->f_crc32 = lzo_crc32(ct->f_crc32, (const uint8_t*)buf, cnt);
+ G.chksum.f_adler32 = lzo_adler32(G.chksum.f_adler32, (const uint8_t*)buf, cnt);
+ G.chksum.f_crc32 = lzo_crc32(G.chksum.f_crc32, (const uint8_t*)buf, cnt);
}
-static uint32_t chksum_getresult(chksum_t *ct, const header_t *h)
+static uint32_t chksum_getresult(uint32_t h_flags32)
{
- return (h->flags & F_H_CRC32) ? ct->f_crc32 : ct->f_adler32;
+ return (h_flags32 & F_H_CRC32) ? G.chksum.f_crc32 : G.chksum.f_adler32;
}
/**********************************************************************/
@@ -575,50 +572,23 @@ static uint32_t read32(void)
xread(0, &v, 4);
return ntohl(v);
}
-
-static void write32(uint32_t v)
-{
- v = htonl(v);
- xwrite(1, &v, 4);
-}
-
-static void f_write(const void* buf, int cnt)
-{
- xwrite(1, buf, cnt);
- add_bytes_to_chksum(&G.chksum_out, buf, cnt);
-}
-
static void f_read(void* buf, int cnt)
{
xread(0, buf, cnt);
- add_bytes_to_chksum(&G.chksum_in, buf, cnt);
+ add_bytes_to_chksum(buf, cnt);
}
-
static int f_read8(void)
{
uint8_t v;
f_read(&v, 1);
return v;
}
-
-static void f_write8(uint8_t v)
-{
- f_write(&v, 1);
-}
-
static unsigned f_read16(void)
{
uint16_t v;
f_read(&v, 2);
return ntohs(v);
}
-
-static void f_write16(uint16_t v)
-{
- v = htons(v);
- f_write(&v, 2);
-}
-
static uint32_t f_read32(void)
{
uint32_t v;
@@ -626,34 +596,30 @@ static uint32_t f_read32(void)
return ntohl(v);
}
-static void f_write32(uint32_t v)
+static void write32(uint32_t v)
{
v = htonl(v);
- f_write(&v, 4);
+ xwrite(1, &v, 4);
}
-
-/**********************************************************************/
-static int lzo_get_method(header_t *h)
+static void f_write(const void* buf, int cnt)
{
- /* check method */
- if (h->method == M_LZO1X_1) {
- if (h->level == 0)
- h->level = 3;
- } else if (h->method == M_LZO1X_1_15) {
- if (h->level == 0)
- h->level = 1;
- } else if (h->method == M_LZO1X_999) {
- if (h->level == 0)
- h->level = 9;
- } else
- return -1; /* not a LZO method */
-
- /* check compression level */
- if (h->level < 1 || h->level > 9)
- return 15;
-
- return 0;
+ xwrite(1, buf, cnt);
+ add_bytes_to_chksum(buf, cnt);
}
+//static void f_write8(uint8_t v)
+//{
+// f_write(&v, 1);
+//}
+//static void f_write16(uint16_t v)
+//{
+// v = htons(v);
+// f_write(&v, 2);
+//}
+//static void f_write32(uint32_t v)
+//{
+// v = htonl(v);
+// f_write(&v, 4);
+//}
/**********************************************************************/
#define LZO_BLOCK_SIZE (256 * 1024l)
@@ -697,9 +663,9 @@ static NOINLINE int lzo_compress(const header_t *h)
break;
/* compute checksum of uncompressed block */
- if (h->flags & F_ADLER32_D)
+ if (h->flags32 & F_ADLER32_D)
d_adler32 = lzo_adler32(ADLER32_INIT_VALUE, b1, src_len);
- if (h->flags & F_CRC32_D)
+ if (h->flags32 & F_CRC32_D)
d_crc32 = lzo_crc32(CRC32_INIT_VALUE, b1, src_len);
/* compress */
@@ -734,16 +700,16 @@ static NOINLINE int lzo_compress(const header_t *h)
}
/* write checksum of uncompressed block */
- if (h->flags & F_ADLER32_D)
+ if (h->flags32 & F_ADLER32_D)
write32(d_adler32);
- if (h->flags & F_CRC32_D)
+ if (h->flags32 & F_CRC32_D)
write32(d_crc32);
if (dst_len < src_len) {
/* write checksum of compressed block */
- if (h->flags & F_ADLER32_C)
+ if (h->flags32 & F_ADLER32_C)
write32(lzo_adler32(ADLER32_INIT_VALUE, b2, dst_len));
- if (h->flags & F_CRC32_C)
+ if (h->flags32 & F_CRC32_C)
write32(lzo_crc32(CRC32_INIT_VALUE, b2, dst_len));
/* write compressed block data */
xwrite(1, b2, dst_len);
@@ -777,7 +743,9 @@ static FAST_FUNC void lzo_check(
/**********************************************************************/
// decompress a file
/**********************************************************************/
-static NOINLINE int lzo_decompress(const header_t *h)
+// used to have "const header_t *h" parameter, but since it uses
+// only flags32 field, changed to receive only that.
+static NOINLINE int lzo_decompress(uint32_t h_flags32)
{
unsigned block_size = LZO_BLOCK_SIZE;
int r;
@@ -822,16 +790,16 @@ static NOINLINE int lzo_decompress(const header_t *h)
}
/* read checksum of uncompressed block */
- if (h->flags & F_ADLER32_D)
+ if (h_flags32 & F_ADLER32_D)
d_adler32 = read32();
- if (h->flags & F_CRC32_D)
+ if (h_flags32 & F_CRC32_D)
d_crc32 = read32();
/* read checksum of compressed block */
if (src_len < dst_len) {
- if (h->flags & F_ADLER32_C)
+ if (h_flags32 & F_ADLER32_C)
c_adler32 = read32();
- if (h->flags & F_CRC32_C)
+ if (h_flags32 & F_CRC32_C)
c_crc32 = read32();
}
@@ -846,11 +814,11 @@ static NOINLINE int lzo_decompress(const header_t *h)
if (!(option_mask32 & OPT_F)) {
/* verify checksum of compressed block */
- if (h->flags & F_ADLER32_C)
+ if (h_flags32 & F_ADLER32_C)
lzo_check(ADLER32_INIT_VALUE,
b1, src_len,
lzo_adler32, c_adler32);
- if (h->flags & F_CRC32_C)
+ if (h_flags32 & F_CRC32_C)
lzo_check(CRC32_INIT_VALUE,
b1, src_len,
lzo_crc32, c_crc32);
@@ -873,11 +841,11 @@ static NOINLINE int lzo_decompress(const header_t *h)
if (!(option_mask32 & OPT_F)) {
/* verify checksum of uncompressed block */
- if (h->flags & F_ADLER32_D)
+ if (h_flags32 & F_ADLER32_D)
lzo_check(ADLER32_INIT_VALUE,
dst, dst_len,
lzo_adler32, d_adler32);
- if (h->flags & F_CRC32_D)
+ if (h_flags32 & F_CRC32_D)
lzo_check(CRC32_INIT_VALUE,
dst, dst_len,
lzo_crc32, d_crc32);
@@ -917,7 +885,7 @@ static NOINLINE int lzo_decompress(const header_t *h)
* -00000020 00 00 2d 67 04 17 00 04 00 00 00 03 ed ec 9d 6d
* +00000020 00 00 10 5f 00 c1 00 04 00 00 00 03 ed ec 9d 6d
* ^^^^^^^^^^^
- * chksum_out
+ * chksum
* The rest is identical.
*/
static const unsigned char lzop_magic[9] ALIGN1 = {
@@ -936,114 +904,115 @@ static void check_magic(void)
/**********************************************************************/
// lzop file header
/**********************************************************************/
-static void write_header(const header_t *h)
+static void write_header(header_t *h)
{
- int l;
+ char *end;
xwrite(1, lzop_magic, sizeof(lzop_magic));
- init_chksum(&G.chksum_out);
+ init_chksum();
- f_write16(h->version);
- f_write16(h->lib_version);
- f_write16(h->version_needed_to_extract);
- f_write8(h->method);
- f_write8(h->level);
- f_write32(h->flags);
- f_write32(h->mode);
- f_write32(h->mtime);
- f_write32(h->gmtdiff);
+ /* Our caller leaves name zero-filled, so len == 0 */
+ end = h->len_and_name+1 + 0; /* 0 is strlen(h->len_and_name+1) */
+ /* Store length byte */
+ /*h->len_and_name[0] = end - (h->len_and_name+1); - zero already */
- l = (int) strlen(h->name);
- f_write8(l);
- if (l)
- f_write(h->name, l);
+ f_write(&h->version_be16, end - (char*)&h->version_be16);
- f_write32(chksum_getresult(&G.chksum_out, h));
+ h->flags32 = htonl(h->flags32); /* native endianness for lzo_compress() */
+
+ /*f_*/write32(chksum_getresult(h->flags32));
}
static int read_header(header_t *h)
{
- int r;
int l;
uint32_t checksum;
+ unsigned h_version;
+ uint8_t h_method, h_level;
- memset(h, 0, sizeof(*h));
- h->version_needed_to_extract = 0x0900; /* first lzop version */
- h->level = 0;
-
- init_chksum(&G.chksum_in);
+ init_chksum();
- h->version = f_read16();
- if (h->version < 0x0900)
+ /* As it stands now, only h->flags32 is used by our caller.
+ * Therefore we don't store many fields in h->field.
+ */
+ h_version = f_read16();
+ if (h_version < 0x0900)
return 3;
- h->lib_version = f_read16();
- if (h->version >= 0x0940) {
- h->version_needed_to_extract = f_read16();
- if (h->version_needed_to_extract > LZOP_VERSION)
+ /* UNUSED h->lib_version_be16 = */ f_read16();
+ if (h_version >= 0x0940) {
+ unsigned h_version_needed_to_extract = f_read16();
+ if (h_version_needed_to_extract > LZOP_VERSION)
return 16;
- if (h->version_needed_to_extract < 0x0900)
+ if (h_version_needed_to_extract < 0x0900) /* first lzop version */
return 3;
}
- h->method = f_read8();
- if (h->version >= 0x0940)
- h->level = f_read8();
- h->flags = f_read32();
- if (h->flags & F_H_FILTER)
+
+ h_method = f_read8();
+ if (h_method <= 0)
+ return 14;
+ h_level = 0;
+ if (h_version >= 0x0940)
+ h_level = f_read8();
+
+ /* former lzo_get_method(h): */
+ if (h_method == M_LZO1X_1) {
+ if (h_level == 0)
+ h_level = 3;
+ } else if (h_method == M_LZO1X_1_15) {
+ if (h_level == 0)
+ h_level = 1;
+ } else if (h_method == M_LZO1X_999) {
+ if (h_level == 0)
+ h_level = 9;
+ } else
+ return -1; /* not a LZO method */
+ /* check compression level */
+ if (h_level < 1 || h_level > 9)
+ return 15;
+
+ h->flags32 = f_read32();
+ if (h->flags32 & F_H_FILTER)
return 16; /* filter not supported */
- h->mode = f_read32();
- h->mtime = f_read32();
- if (h->version >= 0x0940)
- h->gmtdiff = f_read32();
+ /* check reserved flags */
+ if (h->flags32 & F_RESERVED)
+ return -13;
+
+ /* UNUSED h->mode = */ f_read32();
+ /* UNUSED h->mtime = */ f_read32();
+ if (h_version >= 0x0940)
+ /* UNUSED h->gmtdiff = */ f_read32();
l = f_read8();
+ /* UNUSED h->len_and_name[0] = l; */
+ /* UNUSED h->len_and_name[1+l] = 0; */
if (l > 0)
- f_read(h->name, l);
- h->name[l] = 0;
+ f_read(h->len_and_name+1, l);
- checksum = chksum_getresult(&G.chksum_in, h);
- h->header_checksum = f_read32();
- if (h->header_checksum != checksum)
+ checksum = chksum_getresult(h->flags32);
+ if (f_read32() != checksum)
return 2;
- if (h->method <= 0)
- return 14;
- r = lzo_get_method(h);
- if (r != 0)
- return r;
-
- /* check reserved flags */
- if (h->flags & F_RESERVED)
- return -13;
-
/* skip extra field [not used yet] */
- if (h->flags & F_H_EXTRA_FIELD) {
+ if (h->flags32 & F_H_EXTRA_FIELD) {
+ uint32_t extra_field_len;
+ uint32_t extra_field_checksum;
uint32_t k;
/* note: the checksum also covers the length */
- init_chksum(&G.chksum_in);
- h->extra_field_len = f_read32();
- for (k = 0; k < h->extra_field_len; k++)
+ init_chksum();
+ extra_field_len = f_read32();
+ for (k = 0; k < extra_field_len; k++)
f_read8();
- checksum = chksum_getresult(&G.chksum_in, h);
- h->extra_field_checksum = f_read32();
- if (h->extra_field_checksum != checksum)
+ checksum = chksum_getresult(h->flags32);
+ extra_field_checksum = f_read32();
+ if (extra_field_checksum != checksum)
return 3;
}
return 0;
}
-static void p_header(header_t *h)
-{
- int r;
-
- r = read_header(h);
- if (r == 0)
- return;
- bb_error_msg_and_die("header_error %d", r);
-}
-
/**********************************************************************/
// compress
/**********************************************************************/
@@ -1082,18 +1051,21 @@ static int do_lzo_compress(void)
lzo_set_method(h);
- h->version = (LZOP_VERSION & 0xffff);
- h->version_needed_to_extract = 0x0940;
- h->lib_version = lzo_version() & 0xffff;
+ h->version_be16 = htons(LZOP_VERSION & 0xffff);
+ h->version_needed_to_extract_be16 = htons(0x0940);
+ h->lib_version_be16 = htons(lzo_version() & 0xffff);
- h->flags = (F_OS & F_OS_MASK) | (F_CS & F_CS_MASK);
+ h->flags32 = htonl((F_OS & F_OS_MASK) | (F_CS & F_CS_MASK));
if (!(option_mask32 & OPT_F) || h->method == M_LZO1X_999) {
- h->flags |= F_ADLER32_D;
+ h->flags32 |= htonl(F_ADLER32_D);
if (option_mask32 & OPT_C)
- h->flags |= F_ADLER32_C;
+ h->flags32 |= htonl(F_ADLER32_C);
}
+
+ /* write_header() also converts h->flags32 to native endianness */
write_header(h);
+
return lzo_compress(h);
#undef h
}
@@ -1103,11 +1075,14 @@ static int do_lzo_compress(void)
/**********************************************************************/
static int do_lzo_decompress(void)
{
+ int r;
header_t header;
check_magic();
- p_header(&header);
- return lzo_decompress(&header);
+ r = read_header(&header);
+ if (r != 0)
+ bb_error_msg_and_die("header_error %d", r);
+ return lzo_decompress(header.flags32);
}
static char* FAST_FUNC make_new_name_lzop(char *filename, const char *expected_ext UNUSED_PARAM)
@@ -1132,6 +1107,8 @@ static IF_DESKTOP(long long) int FAST_FUNC pack_lzop(transformer_state_t *xstate
int lzop_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int lzop_main(int argc UNUSED_PARAM, char **argv)
{
+ INIT_G();
+
getopt32(argv, OPTION_STRING);
argv += optind;
/* -U is "anti -k", invert bit for bbunpack(): */