X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Flz_sarray.c;h=5e0fa7faff227beb16301f80aac3c95232f0b9e4;hp=881c3c6c15718abd86df6888e51881e193c2ebbf;hb=67e3a69b10498376108c15e5c48b8bb2fc8623e7;hpb=cd9835b342c9956e1e1563afaf96e045aa39fd44 diff --git a/src/lz_sarray.c b/src/lz_sarray.c index 881c3c6c..5e0fa7fa 100644 --- a/src/lz_sarray.c +++ b/src/lz_sarray.c @@ -5,7 +5,7 @@ */ /* - * Copyright (c) 2013 Eric Biggers. All rights reserved. + * Copyright (c) 2013, 2014 Eric Biggers. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -51,17 +51,17 @@ * WARNING: this is for debug use only as it does not necessarily run in linear * time!!! */ static void -verify_suffix_array(const input_idx_t SA[restrict], +verify_suffix_array(const lz_sarray_pos_t SA[restrict], const u8 T[restrict], bool found[restrict], - input_idx_t n) + lz_sarray_pos_t n) { #ifdef ENABLE_LZ_DEBUG /* Ensure the SA contains exactly one of each i in [0, n - 1]. */ - for (input_idx_t i = 0; i < n; i++) + for (lz_sarray_pos_t i = 0; i < n; i++) found[i] = false; - for (input_idx_t r = 0; r < n; r++) { - input_idx_t i = SA[r]; + for (lz_sarray_pos_t r = 0; r < n; r++) { + lz_sarray_pos_t i = SA[r]; LZ_ASSERT(i < n); LZ_ASSERT(!found[i]); found[i] = true; @@ -69,13 +69,13 @@ verify_suffix_array(const input_idx_t SA[restrict], /* Ensure the suffix with rank r is lexicographically lesser than the * suffix with rank (r + 1) for all r in [0, n - 2]. */ - for (input_idx_t r = 0; r < n - 1; r++) { + for (lz_sarray_pos_t r = 0; r < n - 1; r++) { - input_idx_t i1 = SA[r]; - input_idx_t i2 = SA[r + 1]; + lz_sarray_pos_t i1 = SA[r]; + lz_sarray_pos_t i2 = SA[r + 1]; - input_idx_t n1 = n - i1; - input_idx_t n2 = n - i2; + lz_sarray_pos_t n1 = n - i1; + lz_sarray_pos_t n2 = n - i2; int res = memcmp(&T[i1], &T[i2], min(n1, n2)); LZ_ASSERT(res < 0 || (res == 0 && n1 < n2)); @@ -90,11 +90,11 @@ verify_suffix_array(const input_idx_t SA[restrict], * the inverse suffix array is a mapping from suffix position to suffix rank. */ static void -compute_inverse_suffix_array(input_idx_t ISA[restrict], - const input_idx_t SA[restrict], - input_idx_t n) +compute_inverse_suffix_array(lz_sarray_pos_t ISA[restrict], + const lz_sarray_pos_t SA[restrict], + lz_sarray_pos_t n) { - input_idx_t r; + lz_sarray_pos_t r; for (r = 0; r < n; r++) ISA[SA[r]] = r; @@ -111,13 +111,13 @@ compute_inverse_suffix_array(input_idx_t ISA[restrict], * take into account that with bytes in the real world, there is no unique * symbol at the end of the string. */ static void -compute_lcp_array(input_idx_t LCP[restrict], - const input_idx_t SA[restrict], - const input_idx_t ISA[restrict], +compute_lcp_array(lz_sarray_pos_t LCP[restrict], + const lz_sarray_pos_t SA[restrict], + const lz_sarray_pos_t ISA[restrict], const u8 T[restrict], - input_idx_t n) + lz_sarray_pos_t n) { - input_idx_t h, i, r, j, lim; + lz_sarray_pos_t h, i, r, j, lim; h = 0; for (i = 0; i < n; i++) { @@ -141,19 +141,19 @@ compute_lcp_array(input_idx_t LCP[restrict], * WARNING: this is for debug use only as it does not necessarily run in linear * time!!! */ static void -verify_lcp_array(input_idx_t LCP[restrict], - const input_idx_t SA[restrict], +verify_lcp_array(lz_sarray_pos_t LCP[restrict], + const lz_sarray_pos_t SA[restrict], const u8 T[restrict], - input_idx_t n) + lz_sarray_pos_t n) { #ifdef ENABLE_LZ_DEBUG - for (input_idx_t r = 0; r < n - 1; r++) { - input_idx_t i1 = SA[r]; - input_idx_t i2 = SA[r + 1]; - input_idx_t lcp = LCP[r + 1]; + for (lz_sarray_pos_t r = 0; r < n - 1; r++) { + lz_sarray_pos_t i1 = SA[r]; + lz_sarray_pos_t i2 = SA[r + 1]; + lz_sarray_pos_t lcp = LCP[r + 1]; - input_idx_t n1 = n - i1; - input_idx_t n2 = n - i2; + lz_sarray_pos_t n1 = n - i1; + lz_sarray_pos_t n2 = n - i2; LZ_ASSERT(lcp <= min(n1, n2)); @@ -183,19 +183,19 @@ verify_lcp_array(input_idx_t LCP[restrict], */ static void init_salink(struct salink link[restrict], - const input_idx_t LCP[restrict], - const input_idx_t SA[restrict], + const lz_sarray_pos_t LCP[restrict], + const lz_sarray_pos_t SA[restrict], const u8 T[restrict], - input_idx_t n, - input_idx_t max_match_len) + lz_sarray_pos_t n, + lz_sarray_len_t max_match_len) { /* Compute salink.next and salink.lcpnext. */ - link[n - 1].next = ~(input_idx_t)0; + link[n - 1].next = LZ_SARRAY_POS_MAX; link[n - 1].lcpnext = 0; - for (input_idx_t r = n - 2; r != ~(input_idx_t)0; r--) { - input_idx_t t = r + 1; - input_idx_t l = LCP[t]; - while (t != ~(input_idx_t)0 && SA[t] > SA[r]) { + for (lz_sarray_pos_t r = n - 2; r != LZ_SARRAY_POS_MAX; r--) { + lz_sarray_pos_t t = r + 1; + lz_sarray_pos_t l = LCP[t]; + while (t != LZ_SARRAY_POS_MAX && SA[t] > SA[r]) { l = min(l, link[t].lcpnext); t = link[t].next; } @@ -204,12 +204,12 @@ init_salink(struct salink link[restrict], } /* Compute salink.prev and salink.lcpprev. */ - link[0].prev = ~(input_idx_t)0; + link[0].prev = LZ_SARRAY_POS_MAX; link[0].lcpprev = 0; - for (input_idx_t r = 1; r < n; r++) { - input_idx_t t = r - 1; - input_idx_t l = LCP[r]; - while (t != ~(input_idx_t)0 && SA[t] > SA[r]) { + for (lz_sarray_pos_t r = 1; r < n; r++) { + lz_sarray_pos_t t = r - 1; + lz_sarray_pos_t l = LCP[r]; + while (t != LZ_SARRAY_POS_MAX && SA[t] > SA[r]) { l = min(l, link[t].lcpprev); t = link[t].prev; } @@ -224,16 +224,16 @@ init_salink(struct salink link[restrict], * time!!! */ static void verify_salink(const struct salink link[], - const input_idx_t SA[], + const lz_sarray_pos_t SA[], const u8 T[], - input_idx_t n, - input_idx_t max_match_len) + lz_sarray_pos_t n, + lz_sarray_len_t max_match_len) { #ifdef ENABLE_LZ_DEBUG - for (input_idx_t r = 0; r < n; r++) { - for (input_idx_t prev = r; ; ) { + for (lz_sarray_pos_t r = 0; r < n; r++) { + for (lz_sarray_pos_t prev = r; ; ) { if (prev == 0) { - LZ_ASSERT(link[r].prev == ~(input_idx_t)0); + LZ_ASSERT(link[r].prev == LZ_SARRAY_POS_MAX); LZ_ASSERT(link[r].lcpprev == 0); break; } @@ -259,9 +259,9 @@ verify_salink(const struct salink link[], } } - for (input_idx_t next = r; ; ) { + for (lz_sarray_pos_t next = r; ; ) { if (next == n - 1) { - LZ_ASSERT(link[r].next == ~(input_idx_t)0); + LZ_ASSERT(link[r].next == LZ_SARRAY_POS_MAX); LZ_ASSERT(link[r].lcpnext == 0); break; } @@ -301,24 +301,17 @@ verify_salink(const struct salink link[], * any memory that may have been allocated. * * @max_window_size - * The maximum window size to support. + * The maximum window size to support. This must be greater than 0. * - * In the current implementation, the memory needed will be - * (6 * sizeof(input_idx_t) * @max_window_size) bytes. - * For (sizeof(input_idx_t) == 4) that's 24 times the window size. - * - * Memory is saved by saving neither the original window nor the LCP - * (Longest Common Prefix) array; otherwise 29 times the window size would - * be required. (In practice the compressor will likely keep the original - * window around anyway, although based on this property of the - * match-finder it theoretically it could overwrite it with the compressed - * data.) + * The amount of needed memory will depend on this value; see + * lz_sarray_get_needed_memory() for details. * * @min_match_len - * The minimum length of each match to be found. + * The minimum length of each match to be found. Must be greater than 0. * * @max_match_len - * The maximum length of each match to be found. + * The maximum length of each match to be found. Must be greater than or + * equal to @min_match_len. * * @max_matches_to_consider * The maximum number of matches to consider at each position. This should @@ -353,12 +346,16 @@ verify_salink(const struct salink link[], */ bool lz_sarray_init(struct lz_sarray *mf, - input_idx_t max_window_size, - input_idx_t min_match_len, - input_idx_t max_match_len, + lz_sarray_pos_t max_window_size, + lz_sarray_len_t min_match_len, + lz_sarray_len_t max_match_len, u32 max_matches_to_consider, u32 max_matches_to_return) { + LZ_ASSERT(min_match_len > 0); + LZ_ASSERT(max_window_size > 0); + LZ_ASSERT(max_match_len >= min_match_len); + mf->max_window_size = max_window_size; mf->min_match_len = min_match_len; mf->max_match_len = max_match_len; @@ -366,10 +363,16 @@ lz_sarray_init(struct lz_sarray *mf, mf->max_matches_to_return = max_matches_to_return; /* SA and ISA will share the same storage block. */ + if ((u64)2 * max_window_size * sizeof(mf->SA[0]) != + 2 * max_window_size * sizeof(mf->SA[0])) + return false; mf->SA = MALLOC(2 * max_window_size * sizeof(mf->SA[0])); if (mf->SA == NULL) return false; + if ((u64)max_window_size * sizeof(mf->salink[0]) != + max_window_size * sizeof(mf->salink[0])) + return false; mf->salink = MALLOC(max_window_size * sizeof(mf->salink[0])); if (mf->salink == NULL) return false; @@ -377,10 +380,25 @@ lz_sarray_init(struct lz_sarray *mf, return true; } +/* + * Return the number of bytes of memory that lz_sarray_init() would allocate for + * the specified maximum window size. + * + * This should be (20 * @max_window_size) unless the type definitions have been + * changed. + */ u64 -lz_sarray_get_needed_memory(input_idx_t max_window_size) +lz_sarray_get_needed_memory(lz_sarray_pos_t max_window_size) { - return (u64)6 * sizeof(input_idx_t) * max_window_size; + u64 size = 0; + + /* SA and ISA: 8 bytes per position */ + size += (u64)max_window_size * 2 * sizeof(((struct lz_sarray*)0)->SA[0]); + + /* salink: 12 bytes per position */ + size += (u64)max_window_size * sizeof(((struct lz_sarray*)0)->salink[0]); + + return size; } /* @@ -397,9 +415,9 @@ lz_sarray_get_needed_memory(input_idx_t max_window_size) * This function runs in linear time (relative to @n). */ void -lz_sarray_load_window(struct lz_sarray *mf, const u8 T[], input_idx_t n) +lz_sarray_load_window(struct lz_sarray *mf, const u8 T[], lz_sarray_pos_t n) { - input_idx_t *ISA, *LCP; + lz_sarray_pos_t *ISA, *LCP; LZ_ASSERT(n > 0 && n <= mf->max_window_size); @@ -418,7 +436,7 @@ lz_sarray_load_window(struct lz_sarray *mf, const u8 T[], input_idx_t n) >= 256 * sizeof(saidx_t)); LZ_ASSERT(mf->max_window_size * sizeof(mf->salink[0]) >= 256 * 256 * sizeof(saidx_t)); - BUILD_BUG_ON(sizeof(input_idx_t) != sizeof(saidx_t)); + BUILD_BUG_ON(sizeof(lz_sarray_pos_t) != sizeof(saidx_t)); divsufsort(T, mf->SA, n, (saidx_t*)&mf->SA[n], (saidx_t*)mf->salink); @@ -434,7 +452,7 @@ lz_sarray_load_window(struct lz_sarray *mf, const u8 T[], input_idx_t n) * end. This is probably worth it because computing the ISA from the SA * is very fast, and since this match-finder is memory-hungry we'd like * to save as much memory as possible. */ - ISA = (input_idx_t*)mf->salink; + ISA = (lz_sarray_pos_t*)mf->salink; compute_inverse_suffix_array(ISA, mf->SA, n); /* Compute LCP (Longest Common Prefix) array. */