Address review comments

1 files changed, 124 insertions, 0 deletions

diff --git a/client/pool-buffer.c b/client/pool-buffer.c
new file mode 100644
index 00000000..93cfcfc5
--- /dev/null
+++ b/client/pool-buffer.c
@@ -0,0 +1,124 @@
+#define _XOPEN_SOURCE 500
+#include <assert.h>
+#include <cairo/cairo.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <pango/pangocairo.h>
+#include <unistd.h>
+#include <wayland-client.h>
+#include "config.h"
+#include "pool-buffer.h"
+
+static int create_pool_file(size_t size, char **name) {
+        static const char template[] = "sway-client-XXXXXX";
+        const char *path = getenv("XDG_RUNTIME_DIR");
+        if (!path) {
+                return -1;
+        }
+
+        int ts = (path[strlen(path) - 1] == '/');
+
+        *name = malloc(
+                strlen(template) +
+                strlen(path) +
+                (ts ? 0 : 1) + 1);
+        sprintf(*name, "%s%s%s", path, ts ? "" : "/", template);
+
+        int fd = mkstemp(*name);
+
+        if (fd < 0) {
+                return -1;
+        }
+
+        if (ftruncate(fd, size) < 0) {
+                close(fd);
+                return -1;
+        }
+
+        return fd;
+}
+
+static void buffer_release(void *data, struct wl_buffer *wl_buffer) {
+        struct pool_buffer *buffer = data;
+        buffer->busy = false;
+}
+
+static const struct wl_buffer_listener buffer_listener = {
+        .release = buffer_release
+};
+
+static struct pool_buffer *create_buffer(struct wl_shm *shm,
+                struct pool_buffer *buf, int32_t width, int32_t height,
+                uint32_t format) {
+        uint32_t stride = width * 4;
+        uint32_t size = stride * height;
+
+        char *name;
+        int fd = create_pool_file(size, &name);
+        assert(fd);
+        void *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+        struct wl_shm_pool *pool = wl_shm_create_pool(shm, fd, size);
+        buf->buffer = wl_shm_pool_create_buffer(pool, 0,
+                        width, height, stride, format);
+        wl_shm_pool_destroy(pool);
+        close(fd);
+        unlink(name);
+        free(name);
+        fd = -1;
+
+        buf->width = width;
+        buf->height = height;
+        buf->surface = cairo_image_surface_create_for_data(data,
+                        CAIRO_FORMAT_ARGB32, width, height, stride);
+        buf->cairo = cairo_create(buf->surface);
+        buf->pango = pango_cairo_create_context(buf->cairo);
+
+        wl_buffer_add_listener(buf->buffer, &buffer_listener, buf);
+        return buf;
+}
+
+static void destroy_buffer(struct pool_buffer *buffer) {
+        if (buffer->buffer) {
+                wl_buffer_destroy(buffer->buffer);
+        }
+        if (buffer->cairo) {
+                cairo_destroy(buffer->cairo);
+        }
+        if (buffer->surface) {
+                cairo_surface_destroy(buffer->surface);
+        }
+        if (buffer->pango) {
+                g_object_unref(buffer->pango);
+        }
+        memset(buffer, 0, sizeof(struct pool_buffer));
+}
+
+struct pool_buffer *get_next_buffer(struct wl_shm *shm,
+                struct pool_buffer pool[static 2], uint32_t width, uint32_t height) {
+        struct pool_buffer *buffer = NULL;
+
+        for (size_t i = 0; i < 2; ++i) {
+                if (pool[i].busy) {
+                        continue;
+                }
+                buffer = &pool[i];
+        }
+
+        if (!buffer) {
+                return NULL;
+        }
+
+        if (buffer->width != width || buffer->height != height) {
+                destroy_buffer(buffer);
+        }
+
+        if (!buffer->buffer) {
+                if (!create_buffer(shm, buffer, width, height,
+                                        WL_SHM_FORMAT_ARGB8888)) {
+                        return NULL;
+                }
+        }
+        return buffer;
+}