simplify access to buffer, making code a bit smaller
authorDenis Vlasenko <vda.linux@googlemail.com>
Fri, 5 Jan 2007 13:59:05 +0000 (13:59 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Fri, 5 Jan 2007 13:59:05 +0000 (13:59 -0000)
archival/libunarchive/decompress_unlzma.c

index a6902807be2dd8e2099d86b37ddbccfd80e8e360..c1b0a31189466c82231d50e4a20f2d54e82560bc 100644 (file)
@@ -22,7 +22,7 @@
 typedef struct {
        int fd;
        uint8_t *ptr;
-       uint8_t *buffer;
+//     uint8_t *buffer;
        uint8_t *buffer_end;
        int buffer_size;
        uint32_t code;
@@ -30,6 +30,8 @@ typedef struct {
        uint32_t bound;
 } rc_t;
 
+//#define RC_BUFFER ((uint8_t*)(void*)(rc+1))
+#define RC_BUFFER ((uint8_t*)(rc+1))
 
 #define RC_TOP_BITS 24
 #define RC_MOVE_BITS 5
@@ -39,22 +41,24 @@ typedef struct {
 /* Called twice: once at startup and once in rc_normalize() */
 static void rc_read(rc_t * rc)
 {
-       rc->buffer_size = read(rc->fd, rc->buffer, rc->buffer_size);
+       rc->buffer_size = read(rc->fd, RC_BUFFER, rc->buffer_size);
        if (rc->buffer_size <= 0)
                bb_error_msg_and_die("unexpected EOF");
-       rc->ptr = rc->buffer;
-       rc->buffer_end = rc->buffer + rc->buffer_size;
+       rc->ptr = RC_BUFFER;
+       rc->buffer_end = RC_BUFFER + rc->buffer_size;
 }
 
 /* Called once */
-static void rc_init(rc_t * rc, int fd, int buffer_size)
+static rc_t* rc_init(int fd, int buffer_size)
 {
        int i;
+       rc_t* rc;
+
+       rc = xmalloc(sizeof(rc_t) + buffer_size);
 
        rc->fd = fd;
-       rc->buffer = xmalloc(buffer_size);
        rc->buffer_size = buffer_size;
-       rc->buffer_end = rc->buffer + rc->buffer_size;
+       rc->buffer_end = RC_BUFFER + rc->buffer_size;
        rc->ptr = rc->buffer_end;
 
        rc->code = 0;
@@ -64,13 +68,14 @@ static void rc_init(rc_t * rc, int fd, int buffer_size)
                        rc_read(rc);
                rc->code = (rc->code << 8) | *rc->ptr++;
        }
+       return rc;
 }
 
-/* Called once. TODO: bb_maybe_free() */
+/* Called once  */
 static ATTRIBUTE_ALWAYS_INLINE void rc_free(rc_t * rc)
 {
        if (ENABLE_FEATURE_CLEAN_UP)
-               free(rc->buffer);
+               free(rc);
 }
 
 /* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
@@ -163,53 +168,58 @@ typedef struct {
 } __attribute__ ((packed)) lzma_header_t;
 
 
-#define LZMA_BASE_SIZE 1846
-#define LZMA_LIT_SIZE 768
+/* #defines will make compiler to compute/optimize each one with each usage.
+ * Have heart and use enum instead. */
+enum {
+       LZMA_BASE_SIZE = 1846,
+       LZMA_LIT_SIZE  = 768,
+
+       LZMA_NUM_POS_BITS_MAX = 4,
 
-#define LZMA_NUM_POS_BITS_MAX 4
+       LZMA_LEN_NUM_LOW_BITS  = 3,
+       LZMA_LEN_NUM_MID_BITS  = 3,
+       LZMA_LEN_NUM_HIGH_BITS = 8,
 
-#define LZMA_LEN_NUM_LOW_BITS 3
-#define LZMA_LEN_NUM_MID_BITS 3
-#define LZMA_LEN_NUM_HIGH_BITS 8
+       LZMA_LEN_CHOICE     = 0,
+       LZMA_LEN_CHOICE_2   = (LZMA_LEN_CHOICE + 1),
+       LZMA_LEN_LOW        = (LZMA_LEN_CHOICE_2 + 1),
+       LZMA_LEN_MID        = (LZMA_LEN_LOW \
+                             + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
+       LZMA_LEN_HIGH       = (LZMA_LEN_MID \
+                             + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
+       LZMA_NUM_LEN_PROBS  = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
 
-#define LZMA_LEN_CHOICE 0
-#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
-#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
-#define LZMA_LEN_MID (LZMA_LEN_LOW \
-                     + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
-#define LZMA_LEN_HIGH (LZMA_LEN_MID \
-                      +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
-#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
+       LZMA_NUM_STATES     = 12,
+       LZMA_NUM_LIT_STATES = 7,
 
-#define LZMA_NUM_STATES 12
-#define LZMA_NUM_LIT_STATES 7
+       LZMA_START_POS_MODEL_INDEX = 4,
+       LZMA_END_POS_MODEL_INDEX   = 14,
+       LZMA_NUM_FULL_DISTANCES    = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
 
-#define LZMA_START_POS_MODEL_INDEX 4
-#define LZMA_END_POS_MODEL_INDEX 14
-#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
+       LZMA_NUM_POS_SLOT_BITS = 6,
+       LZMA_NUM_LEN_TO_POS_STATES = 4,
 
-#define LZMA_NUM_POS_SLOT_BITS 6
-#define LZMA_NUM_LEN_TO_POS_STATES 4
+       LZMA_NUM_ALIGN_BITS = 4,
 
-#define LZMA_NUM_ALIGN_BITS 4
+       LZMA_MATCH_MIN_LEN  = 2,
 
-#define LZMA_MATCH_MIN_LEN 2
+       LZMA_IS_MATCH       = 0,
+       LZMA_IS_REP         = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
+       LZMA_IS_REP_G0      = (LZMA_IS_REP + LZMA_NUM_STATES),
+       LZMA_IS_REP_G1      = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
+       LZMA_IS_REP_G2      = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
+       LZMA_IS_REP_0_LONG  = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
+       LZMA_POS_SLOT       = (LZMA_IS_REP_0_LONG \
+                             + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
+       LZMA_SPEC_POS       = (LZMA_POS_SLOT \
+                             + (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
+       LZMA_ALIGN          = (LZMA_SPEC_POS \
+                             + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
+       LZMA_LEN_CODER      = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
+       LZMA_REP_LEN_CODER  = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
+       LZMA_LITERAL        = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
+};
 
-#define LZMA_IS_MATCH 0
-#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES <<LZMA_NUM_POS_BITS_MAX))
-#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
-#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
-#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
-#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
-#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
-                      + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
-#define LZMA_SPEC_POS (LZMA_POS_SLOT \
-                      +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
-#define LZMA_ALIGN (LZMA_SPEC_POS \
-                   + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
-#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
-#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
-#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
 
 USE_DESKTOP(long long) int
 unlzma(int src_fd, int dst_fd)
@@ -225,7 +235,7 @@ unlzma(int src_fd, int dst_fd)
        uint16_t *prob_lit;
        int num_bits;
        int num_probs;
-       rc_t rc;
+       rc_t *rc;
        int i, mi;
        uint8_t *buffer;
        uint8_t previous_byte = 0;
@@ -260,16 +270,16 @@ unlzma(int src_fd, int dst_fd)
        for (i = 0; i < num_probs; i++)
                p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 
-       rc_init(&rc, src_fd, 0x10000);
+       rc = rc_init(src_fd, 0x10000);
 
        while (global_pos + buffer_pos < header.dst_size) {
                int pos_state = (buffer_pos + global_pos) & pos_state_mask;
 
                prob =
                        p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
-               if (rc_is_bit_0(&rc, prob)) {
+               if (rc_is_bit_0(rc, prob)) {
                        mi = 1;
-                       rc_update_bit_0(&rc, prob);
+                       rc_update_bit_0(rc, prob);
                        prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE
                                        * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
                                        + (previous_byte >> (8 - lc)))));
@@ -287,7 +297,7 @@ unlzma(int src_fd, int dst_fd)
                                        match_byte <<= 1;
                                        bit = match_byte & 0x100;
                                        prob_lit = prob + 0x100 + bit + mi;
-                                       if (rc_get_bit(&rc, prob_lit, &mi)) {
+                                       if (rc_get_bit(rc, prob_lit, &mi)) {
                                                if (!bit)
                                                        break;
                                        } else {
@@ -298,7 +308,7 @@ unlzma(int src_fd, int dst_fd)
                        }
                        while (mi < 0x100) {
                                prob_lit = prob + mi;
-                               rc_get_bit(&rc, prob_lit, &mi);
+                               rc_get_bit(rc, prob_lit, &mi);
                        }
                        previous_byte = (uint8_t) mi;
 
@@ -320,24 +330,24 @@ unlzma(int src_fd, int dst_fd)
                        int offset;
                        uint16_t *prob_len;
 
-                       rc_update_bit_1(&rc, prob);
+                       rc_update_bit_1(rc, prob);
                        prob = p + LZMA_IS_REP + state;
-                       if (rc_is_bit_0(&rc, prob)) {
-                               rc_update_bit_0(&rc, prob);
+                       if (rc_is_bit_0(rc, prob)) {
+                               rc_update_bit_0(rc, prob);
                                rep3 = rep2;
                                rep2 = rep1;
                                rep1 = rep0;
                                state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
                                prob = p + LZMA_LEN_CODER;
                        } else {
-                               rc_update_bit_1(&rc, prob);
+                               rc_update_bit_1(rc, prob);
                                prob = p + LZMA_IS_REP_G0 + state;
-                               if (rc_is_bit_0(&rc, prob)) {
-                                       rc_update_bit_0(&rc, prob);
+                               if (rc_is_bit_0(rc, prob)) {
+                                       rc_update_bit_0(rc, prob);
                                        prob = (p + LZMA_IS_REP_0_LONG
                                                        + (state << LZMA_NUM_POS_BITS_MAX) + pos_state);
-                                       if (rc_is_bit_0(&rc, prob)) {
-                                               rc_update_bit_0(&rc, prob);
+                                       if (rc_is_bit_0(rc, prob)) {
+                                               rc_update_bit_0(rc, prob);
 
                                                state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
                                                pos = buffer_pos - rep0;
@@ -354,24 +364,24 @@ unlzma(int src_fd, int dst_fd)
                                                }
                                                continue;
                                        } else {
-                                               rc_update_bit_1(&rc, prob);
+                                               rc_update_bit_1(rc, prob);
                                        }
                                } else {
                                        uint32_t distance;
 
-                                       rc_update_bit_1(&rc, prob);
+                                       rc_update_bit_1(rc, prob);
                                        prob = p + LZMA_IS_REP_G1 + state;
-                                       if (rc_is_bit_0(&rc, prob)) {
-                                               rc_update_bit_0(&rc, prob);
+                                       if (rc_is_bit_0(rc, prob)) {
+                                               rc_update_bit_0(rc, prob);
                                                distance = rep1;
                                        } else {
-                                               rc_update_bit_1(&rc, prob);
+                                               rc_update_bit_1(rc, prob);
                                                prob = p + LZMA_IS_REP_G2 + state;
-                                               if (rc_is_bit_0(&rc, prob)) {
-                                                       rc_update_bit_0(&rc, prob);
+                                               if (rc_is_bit_0(rc, prob)) {
+                                                       rc_update_bit_0(rc, prob);
                                                        distance = rep2;
                                                } else {
-                                                       rc_update_bit_1(&rc, prob);
+                                                       rc_update_bit_1(rc, prob);
                                                        distance = rep3;
                                                        rep3 = rep2;
                                                }
@@ -385,30 +395,30 @@ unlzma(int src_fd, int dst_fd)
                        }
 
                        prob_len = prob + LZMA_LEN_CHOICE;
-                       if (rc_is_bit_0(&rc, prob_len)) {
-                               rc_update_bit_0(&rc, prob_len);
+                       if (rc_is_bit_0(rc, prob_len)) {
+                               rc_update_bit_0(rc, prob_len);
                                prob_len = (prob + LZMA_LEN_LOW
                                                        + (pos_state << LZMA_LEN_NUM_LOW_BITS));
                                offset = 0;
                                num_bits = LZMA_LEN_NUM_LOW_BITS;
                        } else {
-                               rc_update_bit_1(&rc, prob_len);
+                               rc_update_bit_1(rc, prob_len);
                                prob_len = prob + LZMA_LEN_CHOICE_2;
-                               if (rc_is_bit_0(&rc, prob_len)) {
-                                       rc_update_bit_0(&rc, prob_len);
+                               if (rc_is_bit_0(rc, prob_len)) {
+                                       rc_update_bit_0(rc, prob_len);
                                        prob_len = (prob + LZMA_LEN_MID
                                                                + (pos_state << LZMA_LEN_NUM_MID_BITS));
                                        offset = 1 << LZMA_LEN_NUM_LOW_BITS;
                                        num_bits = LZMA_LEN_NUM_MID_BITS;
                                } else {
-                                       rc_update_bit_1(&rc, prob_len);
+                                       rc_update_bit_1(rc, prob_len);
                                        prob_len = prob + LZMA_LEN_HIGH;
                                        offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
                                                          + (1 << LZMA_LEN_NUM_MID_BITS));
                                        num_bits = LZMA_LEN_NUM_HIGH_BITS;
                                }
                        }
-                       rc_bit_tree_decode(&rc, prob_len, num_bits, &len);
+                       rc_bit_tree_decode(rc, prob_len, num_bits, &len);
                        len += offset;
 
                        if (state < 4) {
@@ -421,7 +431,7 @@ unlzma(int src_fd, int dst_fd)
                                          LZMA_NUM_LEN_TO_POS_STATES ? len :
                                          LZMA_NUM_LEN_TO_POS_STATES - 1)
                                         << LZMA_NUM_POS_SLOT_BITS);
-                               rc_bit_tree_decode(&rc, prob, LZMA_NUM_POS_SLOT_BITS,
+                               rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
                                                                   &pos_slot);
                                if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
                                        num_bits = (pos_slot >> 1) - 1;
@@ -432,7 +442,7 @@ unlzma(int src_fd, int dst_fd)
                                        } else {
                                                num_bits -= LZMA_NUM_ALIGN_BITS;
                                                while (num_bits--)
-                                                       rep0 = (rep0 << 1) | rc_direct_bit(&rc);
+                                                       rep0 = (rep0 << 1) | rc_direct_bit(rc);
                                                prob = p + LZMA_ALIGN;
                                                rep0 <<= LZMA_NUM_ALIGN_BITS;
                                                num_bits = LZMA_NUM_ALIGN_BITS;
@@ -440,7 +450,7 @@ unlzma(int src_fd, int dst_fd)
                                        i = 1;
                                        mi = 1;
                                        while (num_bits--) {
-                                               if (rc_get_bit(&rc, prob + mi, &mi))
+                                               if (rc_get_bit(rc, prob + mi, &mi))
                                                        rep0 |= i;
                                                i <<= 1;
                                        }
@@ -473,6 +483,6 @@ unlzma(int src_fd, int dst_fd)
        // FIXME: error check
        write(dst_fd, buffer, buffer_pos);
        USE_DESKTOP(total_written += buffer_pos;)
-       rc_free(&rc);
+       rc_free(rc);
        return USE_DESKTOP(total_written) + 0;
 }