initial commit

wayland/buffer.c

@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ * Wayland buffer management.
+ *
+ * Copyright (c) 2024, Richard Acayan. All rights reserved.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <wayland-client-protocol.h>
+
+#include "wayland.h"
+
+static int commit_buffer_resize(struct ufkbd_wl_buffer *ctx);
+
+static void on_buffer_release(void *data, struct wl_buffer *buf)
+{
+	struct ufkbd_wl_buffer *ctx = data;
+
+	if (ctx->resize)
+		commit_buffer_resize(ctx);
+
+	ctx->avail = true;
+}
+
+static const struct wl_buffer_listener buf_listener = {
+	.release = on_buffer_release,
+};
+
+static int commit_buffer_resize(struct ufkbd_wl_buffer *ctx)
+{
+	int ret;
+
+	wl_buffer_destroy(ctx->buf);
+
+	ret = ftruncate(ctx->fd, ctx->size);
+	if (ret == -1) {
+		perror("wl: failed to resize shared memory");
+		return -errno;
+	}
+
+	ctx->ptr = mmap(NULL, ctx->size, PROT_READ | PROT_WRITE, MAP_SHARED, ctx->fd, 0);
+	if (ctx->ptr == MAP_FAILED) {
+		perror("wl: failed to map buffer");
+		return -errno;
+	}
+
+	wl_shm_pool_resize(ctx->pool, ctx->size);
+
+	ctx->buf = wl_shm_pool_create_buffer(ctx->pool, 0,
+					     ctx->width, ctx->height,
+					     ctx->width * 4,
+					     WL_SHM_FORMAT_XRGB8888);
+	if (ctx->buf == NULL) {
+		fprintf(stderr, "wl: lost a buffer to failed resize\n");
+		ctx->avail = false;
+	}
+
+	wl_buffer_add_listener(ctx->buf, &buf_listener, ctx);
+
+	ctx->resize = false;
+
+	return 0;
+}
+
+static void on_wl_shm(void *data,
+		      struct wl_registry *reg,
+		      uint32_t name, uint32_t ver)
+{
+	struct ufkbd_wl_buffer *ctx = data;
+
+	ctx->wl = wl_registry_bind(reg, name, &wl_shm_interface, ver);
+	if (ctx->wl == NULL) {
+		fprintf(stderr, "wl: failed to bind to shared memory\n");
+		return;
+	}
+
+	ctx->pool = wl_shm_create_pool(ctx->wl, ctx->fd, 4);
+	if (ctx->pool == NULL) {
+		fprintf(stderr, "wl: failed to create memory pool\n");
+		return;
+	}
+
+	ctx->buf = wl_shm_pool_create_buffer(ctx->pool, 0,
+					     1, 1, 4,
+					     WL_SHM_FORMAT_XRGB8888);
+	if (ctx->buf == NULL) {
+		fprintf(stderr, "wl: failed to create buffer\n");
+		return;
+	}
+
+	wl_buffer_add_listener(ctx->buf, &buf_listener, ctx);
+}
+
+int ufkbd_wl_buffer_consume(struct ufkbd_wl_buffer *ctx,
+				    struct wl_buffer **buf, void **ptr)
+{
+	if (buf == NULL || ptr == NULL)
+		return -EINVAL;
+
+	if (!ctx->avail)
+		return -EBUSY;
+
+	ctx->avail = false;
+
+	*buf = ctx->buf;
+	*ptr = ctx->ptr;
+
+	return 0;
+}
+
+int ufkbd_wl_buffer_resize(struct ufkbd_wl_buffer *ctx,
+				   uint32_t width, uint32_t height)
+{
+	int ret;
+
+	if (width == 0 && height == 0)
+		return -EINVAL;
+
+	ctx->width = width;
+	ctx->height = height;
+
+	if (ctx->size < ctx->width * ctx->height * 4) {
+		munmap(ctx->ptr, ctx->size);
+
+		ctx->size = ctx->width * ctx->height * 4;
+	}
+
+	if (ctx->avail) {
+		ret = commit_buffer_resize(ctx);
+		if (ret)
+			return ret;
+	} else {
+		ctx->resize = true;
+	}
+
+	return 0;
+}
+
+int ufkbd_wl_buffer_init(struct ufkbd_wl_buffer *ctx,
+				 struct ufkbd_input_wayland *ufkbd_wl,
+				 unsigned int id)
+{
+	intmax_t pid;
+	int ret;
+
+	ctx->ufkbd = ufkbd_wl->ufkbd;
+	ctx->id = id;
+
+	ctx->avail = true;
+	ctx->dirty = false;
+	ctx->resize = false;
+
+	ctx->listener.iface = &wl_shm_interface;
+	ctx->listener.cb = on_wl_shm;
+	ctx->listener.data = ctx;
+
+	pid = getpid();
+
+	snprintf(ctx->path, SHM_PATH_SIZE, "/wl_shm_ufkbd_pid%jd_%u", pid, id);
+	ctx->path[SHM_PATH_SIZE - 1] = '\0';
+
+	ctx->fd = shm_open(ctx->path, O_RDWR | O_CREAT | O_EXCL, 0600);
+	if (ctx->fd == -1) {
+		perror("wl: failed to create shared memory");
+		return -errno;
+	}
+
+	ret = ftruncate(ctx->fd, 4);
+	if (ret) {
+		perror("wl: failed to allocate 4 bytes on shm");
+		ret = -errno;
+		goto err;
+	}
+
+	ctx->ptr = mmap(NULL, 4, PROT_READ | PROT_WRITE, MAP_SHARED, ctx->fd, 0);
+	if (ctx->ptr == MAP_FAILED) {
+		perror("wl: failed to map buffer");
+		ret = -errno;
+		goto err;
+	}
+
+	ret = ufkbd_wl_global_listener_add(ufkbd_wl, &ctx->listener);
+	if (ret)
+		goto err;
+
+	ctx->width = 1; 
+	ctx->height = 1; 
+	ctx->size = 4;
+
+	return 0;
+
+err:
+	close(ctx->fd);
+	shm_unlink(ctx->path);
+	return ret;
+}
+
+void ufkbd_wl_buffer_uninit(struct ufkbd_wl_buffer *ctx)
+{
+	if (ctx->buf != NULL)
+		wl_buffer_destroy(ctx->buf);
+
+	if (ctx->pool != NULL)
+		wl_shm_pool_destroy(ctx->pool);
+
+	if (ctx->wl != NULL)
+		wl_shm_destroy(ctx->wl);
+
+	close(ctx->fd);
+	shm_unlink(ctx->path);
+}