1 files changed, 260 insertions, 0 deletions
diff --git a/src/util/pool.c b/src/util/pool.c
new file mode 100644
index 000000000..16ffa398d
--- /dev/null
+++ b/src/util/pool.c
@@ -0,0 +1,260 @@
+/*
+ * 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 "pool.h"
+
+#include "posix.h"
+#ifndef GIT_WIN32
+#include <unistd.h>
+#endif
+
+struct git_pool_page {
+	git_pool_page *next;
+	size_t size;
+	size_t avail;
+	GIT_ALIGN(char data[GIT_FLEX_ARRAY], 8);
+};
+
+static void *pool_alloc_page(git_pool *pool, size_t size);
+
+#ifndef GIT_DEBUG_POOL
+
+static size_t system_page_size = 0;
+
+int git_pool_global_init(void)
+{
+	if (git__page_size(&system_page_size) < 0)
+		system_page_size = 4096;
+	/* allow space for malloc overhead */
+	system_page_size -= (2 * sizeof(void *)) + sizeof(git_pool_page);
+	return 0;
+}
+
+int git_pool_init(git_pool *pool, size_t item_size)
+{
+	GIT_ASSERT_ARG(pool);
+	GIT_ASSERT_ARG(item_size >= 1);
+
+	memset(pool, 0, sizeof(git_pool));
+	pool->item_size = item_size;
+	pool->page_size = system_page_size;
+
+	return 0;
+}
+
+void git_pool_clear(git_pool *pool)
+{
+	git_pool_page *scan, *next;
+
+	for (scan = pool->pages; scan != NULL; scan = next) {
+		next = scan->next;
+		git__free(scan);
+	}
+
+	pool->pages = NULL;
+}
+
+static void *pool_alloc_page(git_pool *pool, size_t size)
+{
+	git_pool_page *page;
+	const size_t new_page_size = (size <= pool->page_size) ? pool->page_size : size;
+	size_t alloc_size;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, new_page_size, sizeof(git_pool_page)) ||
+		!(page = git__malloc(alloc_size)))
+		return NULL;
+
+	page->size = new_page_size;
+	page->avail = new_page_size - size;
+	page->next = pool->pages;
+
+	pool->pages = page;
+
+	return page->data;
+}
+
+static void *pool_alloc(git_pool *pool, size_t size)
+{
+	git_pool_page *page = pool->pages;
+	void *ptr = NULL;
+
+	if (!page || page->avail < size)
+		return pool_alloc_page(pool, size);
+
+	ptr = &page->data[page->size - page->avail];
+	page->avail -= size;
+
+	return ptr;
+}
+
+uint32_t git_pool__open_pages(git_pool *pool)
+{
+	uint32_t ct = 0;
+	git_pool_page *scan;
+	for (scan = pool->pages; scan != NULL; scan = scan->next) ct++;
+	return ct;
+}
+
+bool git_pool__ptr_in_pool(git_pool *pool, void *ptr)
+{
+	git_pool_page *scan;
+	for (scan = pool->pages; scan != NULL; scan = scan->next)
+		if ((void *)scan->data <= ptr &&
+			(void *)(((char *)scan->data) + scan->size) > ptr)
+			return true;
+	return false;
+}
+
+#else
+
+int git_pool_global_init(void)
+{
+	return 0;
+}
+
+static int git_pool__ptr_cmp(const void * a, const void * b)
+{
+	if(a > b) {
+		return 1;
+	}
+	if(a < b) {
+		return -1;
+	}
+	else {
+		return 0;
+	}
+}
+
+int git_pool_init(git_pool *pool, size_t item_size)
+{
+	GIT_ASSERT_ARG(pool);
+	GIT_ASSERT_ARG(item_size >= 1);
+
+	memset(pool, 0, sizeof(git_pool));
+	pool->item_size = item_size;
+	pool->page_size = git_pool__system_page_size();
+	git_vector_init(&pool->allocations, 100, git_pool__ptr_cmp);
+
+	return 0;
+}
+
+void git_pool_clear(git_pool *pool)
+{
+	git_vector_free_deep(&pool->allocations);
+}
+
+static void *pool_alloc(git_pool *pool, size_t size) {
+	void *ptr = NULL;
+	if((ptr = git__malloc(size)) == NULL) {
+		return NULL;
+	}
+	git_vector_insert_sorted(&pool->allocations, ptr, NULL);
+	return ptr;
+}
+
+bool git_pool__ptr_in_pool(git_pool *pool, void *ptr)
+{
+	size_t pos;
+	return git_vector_bsearch(&pos, &pool->allocations, ptr) != GIT_ENOTFOUND;
+}
+#endif
+
+void git_pool_swap(git_pool *a, git_pool *b)
+{
+	git_pool temp;
+
+	if (a == b)
+		return;
+
+	memcpy(&temp, a, sizeof(temp));
+	memcpy(a, b, sizeof(temp));
+	memcpy(b, &temp, sizeof(temp));
+}
+
+static size_t alloc_size(git_pool *pool, size_t count)
+{
+	const size_t align = sizeof(void *) - 1;
+
+	if (pool->item_size > 1) {
+		const size_t item_size = (pool->item_size + align) & ~align;
+		return item_size * count;
+	}
+
+	return (count + align) & ~align;
+}
+
+void *git_pool_malloc(git_pool *pool, size_t items)
+{
+	return pool_alloc(pool, alloc_size(pool, items));
+}
+
+void *git_pool_mallocz(git_pool *pool, size_t items)
+{
+	const size_t size = alloc_size(pool, items);
+	void *ptr = pool_alloc(pool, size);
+	if (ptr)
+		memset(ptr, 0x0, size);
+	return ptr;
+}
+
+char *git_pool_strndup(git_pool *pool, const char *str, size_t n)
+{
+	char *ptr = NULL;
+
+	GIT_ASSERT_ARG_WITH_RETVAL(pool, NULL);
+	GIT_ASSERT_ARG_WITH_RETVAL(str, NULL);
+	GIT_ASSERT_ARG_WITH_RETVAL(pool->item_size == sizeof(char), NULL);
+
+	if (n == SIZE_MAX)
+		return NULL;
+
+	if ((ptr = git_pool_malloc(pool, (n + 1))) != NULL) {
+		memcpy(ptr, str, n);
+		ptr[n] = '\0';
+	}
+
+	return ptr;
+}
+
+char *git_pool_strdup(git_pool *pool, const char *str)
+{
+	GIT_ASSERT_ARG_WITH_RETVAL(pool, NULL);
+	GIT_ASSERT_ARG_WITH_RETVAL(str, NULL);
+	GIT_ASSERT_ARG_WITH_RETVAL(pool->item_size == sizeof(char), NULL);
+
+	return git_pool_strndup(pool, str, strlen(str));
+}
+
+char *git_pool_strdup_safe(git_pool *pool, const char *str)
+{
+	return str ? git_pool_strdup(pool, str) : NULL;
+}
+
+char *git_pool_strcat(git_pool *pool, const char *a, const char *b)
+{
+	void *ptr;
+	size_t len_a, len_b, total;
+
+	GIT_ASSERT_ARG_WITH_RETVAL(pool, NULL);
+	GIT_ASSERT_ARG_WITH_RETVAL(pool->item_size == sizeof(char), NULL);
+
+	len_a = a ? strlen(a) : 0;
+	len_b = b ? strlen(b) : 0;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&total, len_a, len_b) ||
+		GIT_ADD_SIZET_OVERFLOW(&total, total, 1))
+		return NULL;
+
+	if ((ptr = git_pool_malloc(pool, total)) != NULL) {
+		if (len_a)
+			memcpy(ptr, a, len_a);
+		if (len_b)
+			memcpy(((char *)ptr) + len_a, b, len_b);
+		*(((char *)ptr) + len_a + len_b) = '\0';
+	}
+	return ptr;
+}