1 files changed, 267 insertions, 0 deletions
diff --git a/reftable/basics.c b/reftable/basics.c
new file mode 100644
index 0000000000..9988ebd635
--- /dev/null
+++ b/reftable/basics.c
@@ -0,0 +1,267 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file or at
+ * https://developers.google.com/open-source/licenses/bsd
+ */
+
+#define REFTABLE_ALLOW_BANNED_ALLOCATORS
+#include "basics.h"
+#include "reftable-basics.h"
+#include "reftable-error.h"
+
+static void *(*reftable_malloc_ptr)(size_t sz);
+static void *(*reftable_realloc_ptr)(void *, size_t);
+static void (*reftable_free_ptr)(void *);
+
+void *reftable_malloc(size_t sz)
+{
+	if (!sz)
+		return NULL;
+	if (reftable_malloc_ptr)
+		return (*reftable_malloc_ptr)(sz);
+	return malloc(sz);
+}
+
+void *reftable_realloc(void *p, size_t sz)
+{
+	if (!sz) {
+		reftable_free(p);
+		return NULL;
+	}
+
+	if (reftable_realloc_ptr)
+		return (*reftable_realloc_ptr)(p, sz);
+	return realloc(p, sz);
+}
+
+void reftable_free(void *p)
+{
+	if (reftable_free_ptr)
+		reftable_free_ptr(p);
+	else
+		free(p);
+}
+
+void *reftable_calloc(size_t nelem, size_t elsize)
+{
+	void *p;
+
+	if (nelem && elsize > SIZE_MAX / nelem)
+		return NULL;
+
+	p = reftable_malloc(nelem * elsize);
+	if (!p)
+		return NULL;
+
+	memset(p, 0, nelem * elsize);
+	return p;
+}
+
+char *reftable_strdup(const char *str)
+{
+	size_t len = strlen(str);
+	char *result = reftable_malloc(len + 1);
+	if (!result)
+		return NULL;
+	memcpy(result, str, len + 1);
+	return result;
+}
+
+void reftable_set_alloc(void *(*malloc)(size_t),
+			void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	reftable_malloc_ptr = malloc;
+	reftable_realloc_ptr = realloc;
+	reftable_free_ptr = free;
+}
+
+void reftable_buf_init(struct reftable_buf *buf)
+{
+	struct reftable_buf empty = REFTABLE_BUF_INIT;
+	*buf = empty;
+}
+
+void reftable_buf_release(struct reftable_buf *buf)
+{
+	reftable_free(buf->buf);
+	reftable_buf_init(buf);
+}
+
+void reftable_buf_reset(struct reftable_buf *buf)
+{
+	if (buf->alloc) {
+		buf->len = 0;
+		buf->buf[0] = '\0';
+	}
+}
+
+int reftable_buf_setlen(struct reftable_buf *buf, size_t len)
+{
+	if (len > buf->len)
+		return -1;
+	if (len == buf->len)
+		return 0;
+	buf->buf[len] = '\0';
+	buf->len = len;
+	return 0;
+}
+
+int reftable_buf_cmp(const struct reftable_buf *a, const struct reftable_buf *b)
+{
+	size_t len = a->len < b->len ? a->len : b->len;
+	if (len) {
+		int cmp = memcmp(a->buf, b->buf, len);
+		if (cmp)
+			return cmp;
+	}
+	return a->len < b->len ? -1 : a->len != b->len;
+}
+
+int reftable_buf_add(struct reftable_buf *buf, const void *data, size_t len)
+{
+	size_t newlen = buf->len + len;
+
+	if (newlen + 1 > buf->alloc) {
+		if (REFTABLE_ALLOC_GROW(buf->buf, newlen + 1, buf->alloc))
+			return REFTABLE_OUT_OF_MEMORY_ERROR;
+	}
+
+	memcpy(buf->buf + buf->len, data, len);
+	buf->buf[newlen] = '\0';
+	buf->len = newlen;
+
+	return 0;
+}
+
+int reftable_buf_addstr(struct reftable_buf *buf, const char *s)
+{
+	return reftable_buf_add(buf, s, strlen(s));
+}
+
+char *reftable_buf_detach(struct reftable_buf *buf)
+{
+	char *result = buf->buf;
+	reftable_buf_init(buf);
+	return result;
+}
+
+size_t binsearch(size_t sz, int (*f)(size_t k, void *args), void *args)
+{
+	size_t lo = 0;
+	size_t hi = sz;
+
+	/* Invariants:
+	 *
+	 *  (hi == sz) || f(hi) == true
+	 *  (lo == 0 && f(0) == true) || fi(lo) == false
+	 */
+	while (hi - lo > 1) {
+		size_t mid = lo + (hi - lo) / 2;
+		int ret = f(mid, args);
+		if (ret < 0)
+			return sz;
+
+		if (ret > 0)
+			hi = mid;
+		else
+			lo = mid;
+	}
+
+	if (lo)
+		return hi;
+
+	return f(0, args) ? 0 : 1;
+}
+
+void free_names(char **a)
+{
+	char **p;
+	if (!a) {
+		return;
+	}
+	for (p = a; *p; p++) {
+		reftable_free(*p);
+	}
+	reftable_free(a);
+}
+
+size_t names_length(const char **names)
+{
+	const char **p = names;
+	while (*p)
+		p++;
+	return p - names;
+}
+
+char **parse_names(char *buf, int size)
+{
+	char **names = NULL;
+	size_t names_cap = 0;
+	size_t names_len = 0;
+	char *p = buf;
+	char *end = buf + size;
+
+	while (p < end) {
+		char *next = strchr(p, '\n');
+		if (next && next < end) {
+			*next = 0;
+		} else {
+			next = end;
+		}
+		if (p < next) {
+			if (REFTABLE_ALLOC_GROW(names, names_len + 1,
+						names_cap))
+				goto err;
+
+			names[names_len] = reftable_strdup(p);
+			if (!names[names_len++])
+				goto err;
+		}
+		p = next + 1;
+	}
+
+	if (REFTABLE_ALLOC_GROW(names, names_len + 1, names_cap))
+		goto err;
+	names[names_len] = NULL;
+
+	return names;
+
+err:
+	for (size_t i = 0; i < names_len; i++)
+		reftable_free(names[i]);
+	reftable_free(names);
+	return NULL;
+}
+
+int names_equal(const char **a, const char **b)
+{
+	size_t i = 0;
+	for (; a[i] && b[i]; i++)
+		if (strcmp(a[i], b[i]))
+			return 0;
+	return a[i] == b[i];
+}
+
+size_t common_prefix_size(struct reftable_buf *a, struct reftable_buf *b)
+{
+	size_t p = 0;
+	for (; p < a->len && p < b->len; p++)
+		if (a->buf[p] != b->buf[p])
+			break;
+	return p;
+}
+
+uint32_t hash_size(enum reftable_hash id)
+{
+	if (!id)
+		return REFTABLE_HASH_SIZE_SHA1;
+	switch (id) {
+	case REFTABLE_HASH_SHA1:
+		return REFTABLE_HASH_SIZE_SHA1;
+	case REFTABLE_HASH_SHA256:
+		return REFTABLE_HASH_SIZE_SHA256;
+	}
+	abort();
+}