1 files changed, 354 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 0000000..7c2b86b
--- /dev/null
+++ b/src/buffer.c
@@ -0,0 +1,354 @@
+#include <stdarg.h>
+#include <ctype.h>
+#include <string.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/param.h>
+
+#include "buffer.h"
+
+/* Used as default value for strbuf->ptr so that people can always
+ * assume ptr is non-NULL and zero terminated even for new strbufs.
+ */
+unsigned char strbuf__initbuf[1];
+unsigned char strbuf__oom[1];
+
+#define ENSURE_SIZE(b, d) \
+	if ((d) > buf->asize && strbuf_grow(b, (d)) < 0)\
+		return -1;
+
+void strbuf_init(strbuf *buf, int initial_size)
+{
+	buf->asize = 0;
+	buf->size = 0;
+	buf->ptr = strbuf__initbuf;
+
+	if (initial_size)
+		strbuf_grow(buf, initial_size);
+}
+
+int strbuf_try_grow(strbuf *buf, int target_size, bool mark_oom)
+{
+	unsigned char *new_ptr;
+	int new_size;
+
+	if (buf->ptr == strbuf__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 = realloc(new_ptr, new_size);
+
+	if (!new_ptr) {
+		if (mark_oom)
+			buf->ptr = strbuf__oom;
+		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 strbuf_free(strbuf *buf)
+{
+	if (!buf) return;
+
+	if (buf->ptr != strbuf__initbuf && buf->ptr != strbuf__oom)
+		free(buf->ptr);
+
+	strbuf_init(buf, 0);
+}
+
+void strbuf_clear(strbuf *buf)
+{
+	buf->size = 0;
+
+	if (buf->asize > 0)
+		buf->ptr[0] = '\0';
+}
+
+int strbuf_set(strbuf *buf, const unsigned char *data, int len)
+{
+	if (len <= 0 || data == NULL) {
+		strbuf_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 strbuf_sets(strbuf *buf, const char *string)
+{
+	return strbuf_set(buf,
+		(const unsigned char *)string,
+		string ? strlen(string) : 0);
+}
+
+int strbuf_putc(strbuf *buf, int c)
+{
+	ENSURE_SIZE(buf, buf->size + 2);
+	buf->ptr[buf->size++] = c;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int strbuf_put(strbuf *buf, const unsigned char *data, int len)
+{
+	if (len <= 0)
+		return 0;
+
+	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 strbuf_puts(strbuf *buf, const char *string)
+{
+	return strbuf_put(buf, (const unsigned char *)string, strlen(string));
+}
+
+int strbuf_vprintf(strbuf *buf, const char *format, va_list ap)
+{
+	const int expected_size = buf->size + (strlen(format) * 2);
+	int len;
+
+	ENSURE_SIZE(buf, expected_size);
+
+	while (1) {
+		va_list args;
+		va_copy(args, ap);
+
+		len = vsnprintf(
+			(char *)buf->ptr + buf->size,
+			buf->asize - buf->size,
+			format, args
+		);
+
+		if (len < 0) {
+			free(buf->ptr);
+			buf->ptr = strbuf__oom;
+			return -1;
+		}
+
+		if (len + 1 <= buf->asize - buf->size) {
+			buf->size += len;
+			break;
+		}
+
+		ENSURE_SIZE(buf, buf->size + len + 1);
+	}
+
+	return 0;
+}
+
+int strbuf_printf(strbuf *buf, const char *format, ...)
+{
+	int r;
+	va_list ap;
+
+	va_start(ap, format);
+	r = strbuf_vprintf(buf, format, ap);
+	va_end(ap);
+
+	return r;
+}
+
+void strbuf_copy_cstr(char *data, int datasize, const strbuf *buf)
+{
+	int 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 strbuf_swap(strbuf *buf_a, strbuf *buf_b)
+{
+	strbuf t = *buf_a;
+	*buf_a = *buf_b;
+	*buf_b = t;
+}
+
+unsigned char *strbuf_detach(strbuf *buf)
+{
+	unsigned char *data = buf->ptr;
+
+	if (buf->asize == 0 || buf->ptr == strbuf__oom) {
+		/* return an empty string */
+		return calloc(1, 1);
+	}
+
+	strbuf_init(buf, 0);
+	return data;
+}
+
+void strbuf_attach(strbuf *buf, unsigned char *ptr, int asize)
+{
+	strbuf_free(buf);
+
+	if (ptr) {
+		buf->ptr = ptr;
+		buf->size = strlen((char *)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 {
+		strbuf_grow(buf, asize);
+	}
+}
+
+int strbuf_cmp(const strbuf *a, const strbuf *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 strbuf_strchr(const strbuf *buf, int c, int pos)
+{
+	const unsigned char *p = memchr(buf->ptr + pos, c, buf->size - pos);
+	if (!p)
+		return -1;
+
+	return (int)(p - (const unsigned char *)buf->ptr);
+}
+
+int strbuf_strrchr(const strbuf *buf, int c, int pos)
+{
+	int i;
+
+	for (i = pos; i >= 0; i--) {
+		if (buf->ptr[i] == (unsigned char) c)
+			return i;
+	}
+
+	return -1;
+}
+
+void strbuf_truncate(strbuf *buf, int len)
+{
+	if (len < buf->size) {
+		buf->size = len;
+		buf->ptr[buf->size] = '\0';
+	}
+}
+
+void strbuf_drop(strbuf *buf, int n)
+{
+	if (n > 0) {
+		buf->size = buf->size - n;
+		if (buf->size)
+			memmove(buf->ptr, buf->ptr + n, buf->size);
+
+		buf->ptr[buf->size] = '\0';
+	}
+}
+
+void strbuf_trim(strbuf *buf)
+{
+	int i = 0;
+
+	if (!buf->size)
+		return;
+
+	while (i < buf->size && isspace(buf->ptr[i]))
+		i++;
+
+	strbuf_drop(buf, i);
+
+	/* rtrim */
+	while (buf->size > 0) {
+		if (!isspace(buf->ptr[buf->size - 1]))
+			break;
+
+		buf->size--;
+	}
+
+	buf->ptr[buf->size] = '\0';
+}
+
+// Destructively modify string, collapsing consecutive
+// space and newline characters into a single space.
+void strbuf_normalize_whitespace(strbuf *s)
+{
+	bool last_char_was_space = false;
+	int r, w;
+
+	for (r = 0, w = 0; r < s->size; ++r) {
+		switch (s->ptr[r]) {
+		case ' ':
+		case '\n':
+			if (last_char_was_space)
+				break;
+
+			s->ptr[w++] = ' ';
+			last_char_was_space = true;
+			break;
+
+		default:
+			s->ptr[w++] = s->ptr[r];
+			last_char_was_space = false;
+		}
+	}
+
+	strbuf_truncate(s, w);
+}
+
+// Destructively unescape a string: remove backslashes before punctuation chars.
+extern void strbuf_unescape(strbuf *buf)
+{
+	int r, w;
+
+	for (r = 0, w = 0; r < buf->size; ++r) {
+		if (buf->ptr[r] == '\\' && ispunct(buf->ptr[r + 1]))
+			continue;
+
+		buf->ptr[w++] = buf->ptr[r];
+	}
+
+	strbuf_truncate(buf, w);
+}
+