simplify access to buffer, making code a bit smaller

1 files changed, 90 insertions, 80 deletions

diff --git a/archival/libunarchive/decompress_unlzma.c b/archival/libunarchive/decompress_unlzma.c
index a6902807b..c1b0a3118 100644
--- a/archival/libunarchive/decompress_unlzma.c
+++ b/archival/libunarchive/decompress_unlzma.c
@@ -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;
 }