Move buffer-related functions to a new header and add some more utility functions

1 files changed, 95 insertions, 0 deletions

diff --git a/src/buffer.h b/src/buffer.h
new file mode 100644
index 0000000..5ac9664
--- /dev/null
+++ b/src/buffer.h
@@ -0,0 +1,95 @@
+/*
+  Copyright (c) 2012-2013, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FASTD_BUFFER_H_
+#define _FASTD_BUFFER_H_
+
+#include "log.h"
+
+
+struct fastd_buffer {
+	void *base;
+	size_t base_len;
+
+	void *data;
+	size_t len;
+};
+
+
+static inline fastd_buffer_t fastd_buffer_alloc(const fastd_context_t *ctx, size_t len, size_t head_space, size_t tail_space) {
+	size_t base_len = head_space+len+tail_space;
+	void *ptr;
+	int err = posix_memalign(&ptr, 16, base_len);
+	if (err)
+		exit_error(ctx, "posix_memalign: %s", strerror(err));
+
+	return (fastd_buffer_t){ .base = ptr, .base_len = base_len, .data = ptr+head_space, .len = len };
+}
+
+static inline fastd_buffer_t fastd_buffer_dup(const fastd_context_t *ctx, fastd_buffer_t buffer, size_t head_space, size_t tail_space) {
+	fastd_buffer_t new_buffer = fastd_buffer_alloc(ctx, buffer.len, head_space, tail_space);
+	memcpy(new_buffer.data, buffer.data, buffer.len);
+	return new_buffer;
+}
+
+static inline void fastd_buffer_free(fastd_buffer_t buffer) {
+	free(buffer.base);
+}
+
+
+static inline void fastd_buffer_pull_head(const fastd_context_t *ctx, fastd_buffer_t *buffer, size_t len) {
+	if (len > (size_t)(buffer->data - buffer->base))
+		exit_bug(ctx, "tried to pull buffer across base");
+
+	buffer->data -= len;
+	buffer->len += len;
+}
+
+static inline void fastd_buffer_pull_head_zero(const fastd_context_t *ctx, fastd_buffer_t *buffer, size_t len) {
+	fastd_buffer_pull_head(ctx, buffer, len);
+	memset(buffer->data, 0, len);
+}
+
+static inline void fastd_buffer_pull_head_from(const fastd_context_t *ctx, fastd_buffer_t *buffer, const void *data, size_t len) {
+	fastd_buffer_pull_head(ctx, buffer, len);
+	memcpy(buffer->data, data, len);
+}
+
+
+static inline void fastd_buffer_push_head(const fastd_context_t *ctx, fastd_buffer_t *buffer, size_t len) {
+	if (buffer->len < len)
+		exit_bug(ctx, "tried to push buffer across tail");
+
+	buffer->data += len;
+	buffer->len -= len;
+}
+
+static inline void fastd_buffer_push_head_to(const fastd_context_t *ctx, fastd_buffer_t *buffer, void *data, size_t len) {
+	memcpy(data, buffer->data, len);
+	fastd_buffer_push_head(ctx, buffer, len);
+}
+
+#endif /* _FASTD_BUFFER_H_ */