libobs/util: Add deque

libobs/CMakeLists.txt

@@ -114,6 +114,7 @@ target_sources(
           util/crc32.h
           util/curl/curl-helper.h
           util/darray.h
+          util/deque.h
           util/dstr.c
           util/dstr.h
           util/file-serializer.c
@@ -343,6 +344,7 @@ set(public_headers
     util/config-file.h
     util/crc32.h
     util/darray.h
+    util/deque.h
     util/dstr.h
     util/dstr.hpp
     util/file-serializer.h

libobs/cmake/legacy.cmake

@@ -185,6 +185,7 @@ target_sources(
           util/config-file.h
           util/crc32.c
           util/crc32.h
+          util/deque.h
           util/dstr.c
           util/dstr.h
           util/file-serializer.c

libobs/util/deque.h

@@ -0,0 +1,329 @@
+/*
+ * Copyright (c) 2023 Lain Bailey <lain@obsproject.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include "c99defs.h"
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "bmem.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Double-ended Queue */
+
+struct deque {
+	void *data;
+	size_t size;
+
+	size_t start_pos;
+	size_t end_pos;
+	size_t capacity;
+};
+
+static inline void deque_init(struct deque *dq)
+{
+	memset(dq, 0, sizeof(struct deque));
+}
+
+static inline void deque_free(struct deque *dq)
+{
+	bfree(dq->data);
+	memset(dq, 0, sizeof(struct deque));
+}
+
+static inline void deque_reorder_data(struct deque *dq, size_t new_capacity)
+{
+	size_t difference;
+	uint8_t *data;
+
+	if (!dq->size || !dq->start_pos || dq->end_pos > dq->start_pos)
+		return;
+
+	difference = new_capacity - dq->capacity;
+	data = (uint8_t *)dq->data + dq->start_pos;
+	memmove(data + difference, data, dq->capacity - dq->start_pos);
+	dq->start_pos += difference;
+}
+
+static inline void deque_ensure_capacity(struct deque *dq)
+{
+	size_t new_capacity;
+	if (dq->size <= dq->capacity)
+		return;
+
+	new_capacity = dq->capacity * 2;
+	if (dq->size > new_capacity)
+		new_capacity = dq->size;
+
+	dq->data = brealloc(dq->data, new_capacity);
+	deque_reorder_data(dq, new_capacity);
+	dq->capacity = new_capacity;
+}
+
+static inline void deque_reserve(struct deque *dq, size_t capacity)
+{
+	if (capacity <= dq->capacity)
+		return;
+
+	dq->data = brealloc(dq->data, capacity);
+	deque_reorder_data(dq, capacity);
+	dq->capacity = capacity;
+}
+
+static inline void deque_upsize(struct deque *dq, size_t size)
+{
+	size_t add_size = size - dq->size;
+	size_t new_end_pos = dq->end_pos + add_size;
+
+	if (size <= dq->size)
+		return;
+
+	dq->size = size;
+	deque_ensure_capacity(dq);
+
+	if (new_end_pos > dq->capacity) {
+		size_t back_size = dq->capacity - dq->end_pos;
+		size_t loop_size = add_size - back_size;
+
+		if (back_size)
+			memset((uint8_t *)dq->data + dq->end_pos, 0, back_size);
+
+		memset(dq->data, 0, loop_size);
+		new_end_pos -= dq->capacity;
+	} else {
+		memset((uint8_t *)dq->data + dq->end_pos, 0, add_size);
+	}
+
+	dq->end_pos = new_end_pos;
+}
+
+/** Overwrites data at a specific point in the buffer (relative).  */
+static inline void deque_place(struct deque *dq, size_t position,
+			       const void *data, size_t size)
+{
+	size_t end_point = position + size;
+	size_t data_end_pos;
+
+	if (end_point > dq->size)
+		deque_upsize(dq, end_point);
+
+	position += dq->start_pos;
+	if (position >= dq->capacity)
+		position -= dq->capacity;
+
+	data_end_pos = position + size;
+	if (data_end_pos > dq->capacity) {
+		size_t back_size = data_end_pos - dq->capacity;
+		size_t loop_size = size - back_size;
+
+		memcpy((uint8_t *)dq->data + position, data, loop_size);
+		memcpy(dq->data, (uint8_t *)data + loop_size, back_size);
+	} else {
+		memcpy((uint8_t *)dq->data + position, data, size);
+	}
+}
+
+static inline void deque_push_back(struct deque *dq, const void *data,
+				   size_t size)
+{
+	size_t new_end_pos = dq->end_pos + size;
+
+	dq->size += size;
+	deque_ensure_capacity(dq);
+
+	if (new_end_pos > dq->capacity) {
+		size_t back_size = dq->capacity - dq->end_pos;
+		size_t loop_size = size - back_size;
+
+		if (back_size)
+			memcpy((uint8_t *)dq->data + dq->end_pos, data,
+			       back_size);
+		memcpy(dq->data, (uint8_t *)data + back_size, loop_size);
+
+		new_end_pos -= dq->capacity;
+	} else {
+		memcpy((uint8_t *)dq->data + dq->end_pos, data, size);
+	}
+
+	dq->end_pos = new_end_pos;
+}
+
+static inline void deque_push_front(struct deque *dq, const void *data,
+				    size_t size)
+{
+	dq->size += size;
+	deque_ensure_capacity(dq);
+
+	if (dq->size == size) {
+		dq->start_pos = 0;
+		dq->end_pos = size;
+		memcpy((uint8_t *)dq->data, data, size);
+
+	} else if (dq->start_pos < size) {
+		size_t back_size = size - dq->start_pos;
+
+		if (dq->start_pos)
+			memcpy(dq->data, (uint8_t *)data + back_size,
+			       dq->start_pos);
+
+		dq->start_pos = dq->capacity - back_size;
+		memcpy((uint8_t *)dq->data + dq->start_pos, data, back_size);
+	} else {
+		dq->start_pos -= size;
+		memcpy((uint8_t *)dq->data + dq->start_pos, data, size);
+	}
+}
+
+static inline void deque_push_back_zero(struct deque *dq, size_t size)
+{
+	size_t new_end_pos = dq->end_pos + size;
+
+	dq->size += size;
+	deque_ensure_capacity(dq);
+
+	if (new_end_pos > dq->capacity) {
+		size_t back_size = dq->capacity - dq->end_pos;
+		size_t loop_size = size - back_size;
+
+		if (back_size)
+			memset((uint8_t *)dq->data + dq->end_pos, 0, back_size);
+		memset(dq->data, 0, loop_size);
+
+		new_end_pos -= dq->capacity;
+	} else {
+		memset((uint8_t *)dq->data + dq->end_pos, 0, size);
+	}
+
+	dq->end_pos = new_end_pos;
+}
+
+static inline void deque_push_front_zero(struct deque *dq, size_t size)
+{
+	dq->size += size;
+	deque_ensure_capacity(dq);
+
+	if (dq->size == size) {
+		dq->start_pos = 0;
+		dq->end_pos = size;
+		memset((uint8_t *)dq->data, 0, size);
+
+	} else if (dq->start_pos < size) {
+		size_t back_size = size - dq->start_pos;
+
+		if (dq->start_pos)
+			memset(dq->data, 0, dq->start_pos);
+
+		dq->start_pos = dq->capacity - back_size;
+		memset((uint8_t *)dq->data + dq->start_pos, 0, back_size);
+	} else {
+		dq->start_pos -= size;
+		memset((uint8_t *)dq->data + dq->start_pos, 0, size);
+	}
+}
+
+static inline void deque_peek_front(struct deque *dq, void *data, size_t size)
+{
+	assert(size <= dq->size);
+
+	if (data) {
+		size_t start_size = dq->capacity - dq->start_pos;
+
+		if (start_size < size) {
+			memcpy(data, (uint8_t *)dq->data + dq->start_pos,
+			       start_size);
+			memcpy((uint8_t *)data + start_size, dq->data,
+			       size - start_size);
+		} else {
+			memcpy(data, (uint8_t *)dq->data + dq->start_pos, size);
+		}
+	}
+}
+
+static inline void deque_peek_back(struct deque *dq, void *data, size_t size)
+{
+	assert(size <= dq->size);
+
+	if (data) {
+		size_t back_size = (dq->end_pos ? dq->end_pos : dq->capacity);
+
+		if (back_size < size) {
+			size_t front_size = size - back_size;
+			size_t new_end_pos = dq->capacity - front_size;
+
+			memcpy((uint8_t *)data + (size - back_size), dq->data,
+			       back_size);
+			memcpy(data, (uint8_t *)dq->data + new_end_pos,
+			       front_size);
+		} else {
+			memcpy(data, (uint8_t *)dq->data + dq->end_pos - size,
+			       size);
+		}
+	}
+}
+
+static inline void deque_pop_front(struct deque *dq, void *data, size_t size)
+{
+	deque_peek_front(dq, data, size);
+
+	dq->size -= size;
+	if (!dq->size) {
+		dq->start_pos = dq->end_pos = 0;
+		return;
+	}
+
+	dq->start_pos += size;
+	if (dq->start_pos >= dq->capacity)
+		dq->start_pos -= dq->capacity;
+}
+
+static inline void deque_pop_back(struct deque *dq, void *data, size_t size)
+{
+	deque_peek_back(dq, data, size);
+
+	dq->size -= size;
+	if (!dq->size) {
+		dq->start_pos = dq->end_pos = 0;
+		return;
+	}
+
+	if (dq->end_pos <= size)
+		dq->end_pos = dq->capacity - (size - dq->end_pos);
+	else
+		dq->end_pos -= size;
+}
+
+static inline void *deque_data(struct deque *dq, size_t idx)
+{
+	uint8_t *ptr = (uint8_t *)dq->data;
+	size_t offset = dq->start_pos + idx;
+
+	if (idx >= dq->size)
+		return NULL;
+
+	if (offset >= dq->capacity)
+		offset -= dq->capacity;
+
+	return ptr + offset;
+}
+
+#ifdef __cplusplus
+}
+#endif