1 files changed, 461 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 000000000..783a36eb8
--- /dev/null
+++ b/src/buffer.c
@@ -0,0 +1,461 @@
+/*
+ * Copyright (C) 2009-2012 the libgit2 contributors
+ *
+ * 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 "buffer.h"
+#include "posix.h"
+#include <stdarg.h>
+#include <ctype.h>
+
+/* Used as default value for git_buf->ptr so that people can always
+ * assume ptr is non-NULL and zero terminated even for new git_bufs.
+ */
+char git_buf__initbuf[1];
+
+char git_buf__oom[1];
+
+#define ENSURE_SIZE(b, d) \
+	if ((d) > buf->asize && git_buf_grow(b, (d)) < 0)\
+		return -1;
+
+
+void git_buf_init(git_buf *buf, size_t initial_size)
+{
+	buf->asize = 0;
+	buf->size = 0;
+	buf->ptr = git_buf__initbuf;
+
+	if (initial_size)
+		git_buf_grow(buf, initial_size);
+}
+
+int git_buf_grow(git_buf *buf, size_t target_size)
+{
+	int error = git_buf_try_grow(buf, target_size);
+	if (error != 0)
+		buf->ptr = git_buf__oom;
+	return error;
+}
+
+int git_buf_try_grow(git_buf *buf, size_t target_size)
+{
+	char *new_ptr;
+	size_t new_size;
+
+	if (buf->ptr == git_buf__oom)
+		return -1;
+
+	if (target_size <= buf->asize)
+		return 0;
+
+	if (buf->asize == 0) {
+		new_size = target_size;
+		new_ptr = NULL;
+	} else {
+		new_size = buf->asize;
+		new_ptr = buf->ptr;
+	}
+
+	/* grow the buffer size by 1.5, until it's big enough
+	 * to fit our target size */
+	while (new_size < target_size)
+		new_size = (new_size << 1) - (new_size >> 1);
+
+	/* round allocation up to multiple of 8 */
+	new_size = (new_size + 7) & ~7;
+
+	new_ptr = git__realloc(new_ptr, new_size);
+	if (!new_ptr)
+		return -1;
+
+	buf->asize = new_size;
+	buf->ptr   = new_ptr;
+
+	/* truncate the existing buffer size if necessary */
+	if (buf->size >= buf->asize)
+		buf->size = buf->asize - 1;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+void git_buf_free(git_buf *buf)
+{
+	if (!buf) return;
+
+	if (buf->ptr != git_buf__initbuf && buf->ptr != git_buf__oom)
+		git__free(buf->ptr);
+
+	git_buf_init(buf, 0);
+}
+
+void git_buf_clear(git_buf *buf)
+{
+	buf->size = 0;
+	if (buf->asize > 0)
+		buf->ptr[0] = '\0';
+}
+
+int git_buf_set(git_buf *buf, const char *data, size_t len)
+{
+	if (len == 0 || data == NULL) {
+		git_buf_clear(buf);
+	} else {
+		if (data != buf->ptr) {
+			ENSURE_SIZE(buf, len + 1);
+			memmove(buf->ptr, data, len);
+		}
+		buf->size = len;
+		buf->ptr[buf->size] = '\0';
+	}
+	return 0;
+}
+
+int git_buf_sets(git_buf *buf, const char *string)
+{
+	return git_buf_set(buf, string, string ? strlen(string) : 0);
+}
+
+int git_buf_putc(git_buf *buf, char c)
+{
+	ENSURE_SIZE(buf, buf->size + 2);
+	buf->ptr[buf->size++] = c;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int git_buf_put(git_buf *buf, const char *data, size_t len)
+{
+	ENSURE_SIZE(buf, buf->size + len + 1);
+	memmove(buf->ptr + buf->size, data, len);
+	buf->size += len;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int git_buf_puts(git_buf *buf, const char *string)
+{
+	assert(string);
+	return git_buf_put(buf, string, strlen(string));
+}
+
+int git_buf_vprintf(git_buf *buf, const char *format, va_list ap)
+{
+	int len;
+
+	ENSURE_SIZE(buf, buf->size + (strlen(format) * 2));
+
+	while (1) {
+		va_list args;
+		va_copy(args, ap);
+
+		len = p_vsnprintf(
+			buf->ptr + buf->size,
+			buf->asize - buf->size,
+			format, args
+		);
+
+		if (len < 0) {
+			git__free(buf->ptr);
+			buf->ptr = git_buf__oom;
+			return -1;
+		}
+
+		if ((size_t)len + 1 <= buf->asize - buf->size) {
+			buf->size += len;
+			break;
+		}
+
+		ENSURE_SIZE(buf, buf->size + len + 1);
+	}
+
+	return 0;
+}
+
+int git_buf_printf(git_buf *buf, const char *format, ...)
+{
+	int r;
+	va_list ap;
+
+	va_start(ap, format);
+	r = git_buf_vprintf(buf, format, ap);
+	va_end(ap);
+
+	return r;
+}
+
+void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf)
+{
+	size_t copylen;
+
+	assert(data && datasize && buf);
+
+	data[0] = '\0';
+
+	if (buf->size == 0 || buf->asize <= 0)
+		return;
+
+	copylen = buf->size;
+	if (copylen > datasize - 1)
+		copylen = datasize - 1;
+	memmove(data, buf->ptr, copylen);
+	data[copylen] = '\0';
+}
+
+void git_buf_consume(git_buf *buf, const char *end)
+{
+	if (end > buf->ptr && end <= buf->ptr + buf->size) {
+		size_t consumed = end - buf->ptr;
+		memmove(buf->ptr, end, buf->size - consumed);
+		buf->size -= consumed;
+		buf->ptr[buf->size] = '\0';
+	}
+}
+
+void git_buf_truncate(git_buf *buf, size_t len)
+{
+	if (len < buf->size) {
+		buf->size = len;
+		buf->ptr[buf->size] = '\0';
+	}
+}
+
+void git_buf_rtruncate_at_char(git_buf *buf, char separator)
+{
+	ssize_t idx = git_buf_rfind_next(buf, separator);
+	git_buf_truncate(buf, idx < 0 ? 0 : (size_t)idx);
+}
+
+void git_buf_swap(git_buf *buf_a, git_buf *buf_b)
+{
+	git_buf t = *buf_a;
+	*buf_a = *buf_b;
+	*buf_b = t;
+}
+
+char *git_buf_detach(git_buf *buf)
+{
+	char *data = buf->ptr;
+
+	if (buf->asize == 0 || buf->ptr == git_buf__oom)
+		return NULL;
+
+	git_buf_init(buf, 0);
+
+	return data;
+}
+
+void git_buf_attach(git_buf *buf, char *ptr, size_t asize)
+{
+	git_buf_free(buf);
+
+	if (ptr) {
+		buf->ptr = ptr;
+		buf->size = strlen(ptr);
+		if (asize)
+			buf->asize = (asize < buf->size) ? buf->size + 1 : asize;
+		else /* pass 0 to fall back on strlen + 1 */
+			buf->asize = buf->size + 1;
+	} else {
+		git_buf_grow(buf, asize);
+	}
+}
+
+int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...)
+{
+	va_list ap;
+	int i;
+	size_t total_size = 0, original_size = buf->size;
+	char *out, *original = buf->ptr;
+
+	if (buf->size > 0 && buf->ptr[buf->size - 1] != separator)
+		++total_size; /* space for initial separator */
+
+	/* Make two passes to avoid multiple reallocation */
+
+	va_start(ap, nbuf);
+	for (i = 0; i < nbuf; ++i) {
+		const char* segment;
+		size_t segment_len;
+
+		segment = va_arg(ap, const char *);
+		if (!segment)
+			continue;
+
+		segment_len = strlen(segment);
+		total_size += segment_len;
+		if (segment_len == 0 || segment[segment_len - 1] != separator)
+			++total_size; /* space for separator */
+	}
+	va_end(ap);
+
+	/* expand buffer if needed */
+	if (total_size == 0)
+		return 0;
+	if (git_buf_grow(buf, buf->size + total_size + 1) < 0)
+		return -1;
+
+	out = buf->ptr + buf->size;
+
+	/* append separator to existing buf if needed */
+	if (buf->size > 0 && out[-1] != separator)
+		*out++ = separator;
+
+	va_start(ap, nbuf);
+	for (i = 0; i < nbuf; ++i) {
+		const char* segment;
+		size_t segment_len;
+
+		segment = va_arg(ap, const char *);
+		if (!segment)
+			continue;
+
+		/* deal with join that references buffer's original content */
+		if (segment >= original && segment < original + original_size) {
+			size_t offset = (segment - original);
+			segment = buf->ptr + offset;
+			segment_len = original_size - offset;
+		} else {
+			segment_len = strlen(segment);
+		}
+
+		/* skip leading separators */
+		if (out > buf->ptr && out[-1] == separator)
+			while (segment_len > 0 && *segment == separator) {
+				segment++;
+				segment_len--;
+			}
+
+		/* copy over next buffer */
+		if (segment_len > 0) {
+			memmove(out, segment, segment_len);
+			out += segment_len;
+		}
+
+		/* append trailing separator (except for last item) */
+		if (i < nbuf - 1 && out > buf->ptr && out[-1] != separator)
+			*out++ = separator;
+	}
+	va_end(ap);
+
+	/* set size based on num characters actually written */
+	buf->size = out - buf->ptr;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+int git_buf_join(
+	git_buf *buf,
+	char separator,
+	const char *str_a,
+	const char *str_b)
+{
+	size_t strlen_a = str_a ? strlen(str_a) : 0;
+	size_t strlen_b = strlen(str_b);
+	int need_sep = 0;
+	ssize_t offset_a = -1;
+
+	/* not safe to have str_b point internally to the buffer */
+	assert(str_b < buf->ptr || str_b > buf->ptr + buf->size);
+
+	/* figure out if we need to insert a separator */
+	if (separator && strlen_a) {
+		while (*str_b == separator) { str_b++; strlen_b--; }
+		if (str_a[strlen_a - 1] != separator)
+			need_sep = 1;
+	}
+
+	/* str_a could be part of the buffer */
+	if (str_a >= buf->ptr && str_a < buf->ptr + buf->size)
+		offset_a = str_a - buf->ptr;
+
+	if (git_buf_grow(buf, strlen_a + strlen_b + need_sep + 1) < 0)
+		return -1;
+
+	/* fix up internal pointers */
+	if (offset_a >= 0)
+		str_a = buf->ptr + offset_a;
+
+	/* do the actual copying */
+	if (offset_a != 0)
+		memmove(buf->ptr, str_a, strlen_a);
+	if (need_sep)
+		buf->ptr[strlen_a] = separator;
+	memcpy(buf->ptr + strlen_a + need_sep, str_b, strlen_b);
+
+	buf->size = strlen_a + strlen_b + need_sep;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+void git_buf_rtrim(git_buf *buf)
+{
+	while (buf->size > 0) {
+		if (!git__isspace(buf->ptr[buf->size - 1]))
+			break;
+
+		buf->size--;
+	}
+
+	buf->ptr[buf->size] = '\0';
+}
+
+int git_buf_cmp(const git_buf *a, const git_buf *b)
+{
+	int result = memcmp(a->ptr, b->ptr, min(a->size, b->size));
+	return (result != 0) ? result :
+		(a->size < b->size) ? -1 : (a->size > b->size) ? 1 : 0;
+}
+
+int git_buf_common_prefix(git_buf *buf, const git_strarray *strings)
+{
+	size_t i;
+	const char *str, *pfx;
+
+	git_buf_clear(buf);
+
+	if (!strings || !strings->count)
+		return 0;
+
+	/* initialize common prefix to first string */
+	if (git_buf_sets(buf, strings->strings[0]) < 0)
+		return -1;
+
+	/* go through the rest of the strings, truncating to shared prefix */
+	for (i = 1; i < strings->count; ++i) {
+
+		for (str = strings->strings[i], pfx = buf->ptr;
+			 *str && *str == *pfx; str++, pfx++)
+			/* scanning */;
+
+		git_buf_truncate(buf, pfx - buf->ptr);
+
+		if (!buf->size)
+			break;
+	}
+
+	return 0;
+}
+
+bool git_buf_is_binary(const git_buf *buf)
+{
+	size_t i;
+	int printable = 0, nonprintable = 0;
+
+	for (i = 0; i < buf->size; i++) {
+		unsigned char c = buf->ptr[i];
+		if (c > 0x1F && c < 0x7F)
+			printable++;
+		else if (c == '\0')
+			return true;
+		else if (!git__isspace(c))
+			nonprintable++;
+	}
+
+	return ((printable >> 7) < nonprintable);
+}
+