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Diffstat (limited to 'src/util/vector.c')
-rw-r--r-- | src/util/vector.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/src/util/vector.c b/src/util/vector.c new file mode 100644 index 0000000..4a4bc8c --- /dev/null +++ b/src/util/vector.c @@ -0,0 +1,431 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ + +#include "vector.h" + +#include "integer.h" + +/* In elements, not bytes */ +#define MIN_ALLOCSIZE 8 + +GIT_INLINE(size_t) compute_new_size(git_vector *v) +{ + size_t new_size = v->_alloc_size; + + /* Use a resize factor of 1.5, which is quick to compute using integer + * instructions and less than the golden ratio (1.618...) */ + if (new_size < MIN_ALLOCSIZE) + new_size = MIN_ALLOCSIZE; + else if (new_size <= (SIZE_MAX / 3) * 2) + new_size += new_size / 2; + else + new_size = SIZE_MAX; + + return new_size; +} + +GIT_INLINE(int) resize_vector(git_vector *v, size_t new_size) +{ + void *new_contents; + + if (new_size == 0) + return 0; + + new_contents = git__reallocarray(v->contents, new_size, sizeof(void *)); + GIT_ERROR_CHECK_ALLOC(new_contents); + + v->_alloc_size = new_size; + v->contents = new_contents; + + return 0; +} + +int git_vector_size_hint(git_vector *v, size_t size_hint) +{ + if (v->_alloc_size >= size_hint) + return 0; + return resize_vector(v, size_hint); +} + +int git_vector_dup(git_vector *v, const git_vector *src, git_vector_cmp cmp) +{ + GIT_ASSERT_ARG(v); + GIT_ASSERT_ARG(src); + + v->_alloc_size = 0; + v->contents = NULL; + v->_cmp = cmp ? cmp : src->_cmp; + v->length = src->length; + v->flags = src->flags; + if (cmp != src->_cmp) + git_vector_set_sorted(v, 0); + + if (src->length) { + size_t bytes; + GIT_ERROR_CHECK_ALLOC_MULTIPLY(&bytes, src->length, sizeof(void *)); + v->contents = git__malloc(bytes); + GIT_ERROR_CHECK_ALLOC(v->contents); + v->_alloc_size = src->length; + memcpy(v->contents, src->contents, bytes); + } + + return 0; +} + +void git_vector_free(git_vector *v) +{ + if (!v) + return; + + git__free(v->contents); + v->contents = NULL; + + v->length = 0; + v->_alloc_size = 0; +} + +void git_vector_free_deep(git_vector *v) +{ + size_t i; + + if (!v) + return; + + for (i = 0; i < v->length; ++i) { + git__free(v->contents[i]); + v->contents[i] = NULL; + } + + git_vector_free(v); +} + +int git_vector_init(git_vector *v, size_t initial_size, git_vector_cmp cmp) +{ + GIT_ASSERT_ARG(v); + + v->_alloc_size = 0; + v->_cmp = cmp; + v->length = 0; + v->flags = GIT_VECTOR_SORTED; + v->contents = NULL; + + return resize_vector(v, max(initial_size, MIN_ALLOCSIZE)); +} + +void **git_vector_detach(size_t *size, size_t *asize, git_vector *v) +{ + void **data = v->contents; + + if (size) + *size = v->length; + if (asize) + *asize = v->_alloc_size; + + v->_alloc_size = 0; + v->length = 0; + v->contents = NULL; + + return data; +} + +int git_vector_insert(git_vector *v, void *element) +{ + GIT_ASSERT_ARG(v); + + if (v->length >= v->_alloc_size && + resize_vector(v, compute_new_size(v)) < 0) + return -1; + + v->contents[v->length++] = element; + + git_vector_set_sorted(v, v->length <= 1); + + return 0; +} + +int git_vector_insert_sorted( + git_vector *v, void *element, int (*on_dup)(void **old, void *new)) +{ + int result; + size_t pos; + + GIT_ASSERT_ARG(v); + GIT_ASSERT(v->_cmp); + + if (!git_vector_is_sorted(v)) + git_vector_sort(v); + + if (v->length >= v->_alloc_size && + resize_vector(v, compute_new_size(v)) < 0) + return -1; + + /* If we find the element and have a duplicate handler callback, + * invoke it. If it returns non-zero, then cancel insert, otherwise + * proceed with normal insert. + */ + if (!git__bsearch(v->contents, v->length, element, v->_cmp, &pos) && + on_dup && (result = on_dup(&v->contents[pos], element)) < 0) + return result; + + /* shift elements to the right */ + if (pos < v->length) + memmove(v->contents + pos + 1, v->contents + pos, + (v->length - pos) * sizeof(void *)); + + v->contents[pos] = element; + v->length++; + + return 0; +} + +void git_vector_sort(git_vector *v) +{ + if (git_vector_is_sorted(v) || !v->_cmp) + return; + + if (v->length > 1) + git__tsort(v->contents, v->length, v->_cmp); + git_vector_set_sorted(v, 1); +} + +int git_vector_bsearch2( + size_t *at_pos, + git_vector *v, + git_vector_cmp key_lookup, + const void *key) +{ + GIT_ASSERT_ARG(v); + GIT_ASSERT_ARG(key); + GIT_ASSERT(key_lookup); + + /* need comparison function to sort the vector */ + if (!v->_cmp) + return -1; + + git_vector_sort(v); + + return git__bsearch(v->contents, v->length, key, key_lookup, at_pos); +} + +int git_vector_search2( + size_t *at_pos, const git_vector *v, git_vector_cmp key_lookup, const void *key) +{ + size_t i; + + GIT_ASSERT_ARG(v); + GIT_ASSERT_ARG(key); + GIT_ASSERT(key_lookup); + + for (i = 0; i < v->length; ++i) { + if (key_lookup(key, v->contents[i]) == 0) { + if (at_pos) + *at_pos = i; + + return 0; + } + } + + return GIT_ENOTFOUND; +} + +static int strict_comparison(const void *a, const void *b) +{ + return (a == b) ? 0 : -1; +} + +int git_vector_search(size_t *at_pos, const git_vector *v, const void *entry) +{ + return git_vector_search2(at_pos, v, v->_cmp ? v->_cmp : strict_comparison, entry); +} + +int git_vector_remove(git_vector *v, size_t idx) +{ + size_t shift_count; + + GIT_ASSERT_ARG(v); + + if (idx >= v->length) + return GIT_ENOTFOUND; + + shift_count = v->length - idx - 1; + + if (shift_count) + memmove(&v->contents[idx], &v->contents[idx + 1], + shift_count * sizeof(void *)); + + v->length--; + return 0; +} + +void git_vector_pop(git_vector *v) +{ + if (v->length > 0) + v->length--; +} + +void git_vector_uniq(git_vector *v, void (*git_free_cb)(void *)) +{ + git_vector_cmp cmp; + size_t i, j; + + if (v->length <= 1) + return; + + git_vector_sort(v); + cmp = v->_cmp ? v->_cmp : strict_comparison; + + for (i = 0, j = 1 ; j < v->length; ++j) + if (!cmp(v->contents[i], v->contents[j])) { + if (git_free_cb) + git_free_cb(v->contents[i]); + + v->contents[i] = v->contents[j]; + } else + v->contents[++i] = v->contents[j]; + + v->length -= j - i - 1; +} + +void git_vector_remove_matching( + git_vector *v, + int (*match)(const git_vector *v, size_t idx, void *payload), + void *payload) +{ + size_t i, j; + + for (i = 0, j = 0; j < v->length; ++j) { + v->contents[i] = v->contents[j]; + + if (!match(v, i, payload)) + i++; + } + + v->length = i; +} + +void git_vector_clear(git_vector *v) +{ + v->length = 0; + git_vector_set_sorted(v, 1); +} + +void git_vector_swap(git_vector *a, git_vector *b) +{ + git_vector t; + + if (a != b) { + memcpy(&t, a, sizeof(t)); + memcpy(a, b, sizeof(t)); + memcpy(b, &t, sizeof(t)); + } +} + +int git_vector_resize_to(git_vector *v, size_t new_length) +{ + if (new_length > v->_alloc_size && + resize_vector(v, new_length) < 0) + return -1; + + if (new_length > v->length) + memset(&v->contents[v->length], 0, + sizeof(void *) * (new_length - v->length)); + + v->length = new_length; + + return 0; +} + +int git_vector_insert_null(git_vector *v, size_t idx, size_t insert_len) +{ + size_t new_length; + + GIT_ASSERT_ARG(insert_len > 0); + GIT_ASSERT_ARG(idx <= v->length); + + GIT_ERROR_CHECK_ALLOC_ADD(&new_length, v->length, insert_len); + + if (new_length > v->_alloc_size && resize_vector(v, new_length) < 0) + return -1; + + memmove(&v->contents[idx + insert_len], &v->contents[idx], + sizeof(void *) * (v->length - idx)); + memset(&v->contents[idx], 0, sizeof(void *) * insert_len); + + v->length = new_length; + return 0; +} + +int git_vector_remove_range(git_vector *v, size_t idx, size_t remove_len) +{ + size_t new_length = v->length - remove_len; + size_t end_idx = 0; + + GIT_ASSERT_ARG(remove_len > 0); + + if (git__add_sizet_overflow(&end_idx, idx, remove_len)) + GIT_ASSERT(0); + + GIT_ASSERT(end_idx <= v->length); + + if (end_idx < v->length) + memmove(&v->contents[idx], &v->contents[end_idx], + sizeof(void *) * (v->length - end_idx)); + + memset(&v->contents[new_length], 0, sizeof(void *) * remove_len); + + v->length = new_length; + return 0; +} + +int git_vector_set(void **old, git_vector *v, size_t position, void *value) +{ + if (position + 1 > v->length) { + if (git_vector_resize_to(v, position + 1) < 0) + return -1; + } + + if (old != NULL) + *old = v->contents[position]; + + v->contents[position] = value; + + return 0; +} + +int git_vector_verify_sorted(const git_vector *v) +{ + size_t i; + + if (!git_vector_is_sorted(v)) + return -1; + + for (i = 1; i < v->length; ++i) { + if (v->_cmp(v->contents[i - 1], v->contents[i]) > 0) + return -1; + } + + return 0; +} + +void git_vector_reverse(git_vector *v) +{ + size_t a, b; + + if (v->length == 0) + return; + + a = 0; + b = v->length - 1; + + while (a < b) { + void *tmp = v->contents[a]; + v->contents[a] = v->contents[b]; + v->contents[b] = tmp; + a++; + b--; + } +} |