From c978f746058497ddd9ddc9cf3e156c4453e487f1 Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pjm@nac.net>
Date: Fri, 15 Feb 2013 15:28:42 -0500
Subject: Add resource manager and move src/image.*.

---
(limited to 'src/resources/resource.c')

diff --git a/src/resources/resource.c b/src/resources/resource.c
new file mode 100644
index 0000000..ebfcf27
--- /dev/null
+++ b/src/resources/resource.c
@@ -0,0 +1,87 @@
+#include <stdlib.h>
+#include <string.h>
+#include "resource.h"
+
+#include "../logging.h"
+
+inline void *
+resource_alloc(const char *path, size_t size)
+{
+	void *new_res;
+
+	debug("Allocating resource \"%s\"...", path);
+	new_res = malloc(size);
+	if (new_res == NULL) {
+		err(1, "Failed to allocate resource \"%s\"", path);
+		return NULL;
+	}
+	memset(new_res, 0, size);
+
+	return new_res;
+}
+
+struct resource *
+resource_get(struct resource_table *resources, const char *path)
+{
+	struct resource *res;
+
+	for (res = resources->head; res != NULL; res = res->next) {
+		if (strcmp(res->path, path) == 0) {
+			debug("Found resource \"%s\"", path);
+			return res;
+		}
+	}
+
+	return NULL;
+}
+
+void
+resource_add(struct resource_table *resources, const char *path,
+		struct resource *new_res)
+{
+	new_res->path = strdup(path);
+	new_res->prev = resources->tail;
+	new_res->next = NULL;
+
+	if (resources->head == NULL) {
+		resources->head = new_res;
+	} else {
+		resources->tail->next = new_res;
+	}
+	resources->tail = new_res;
+}
+
+/* XXX: Not thread-safe. */
+void
+resource_use(struct resource *resource)
+{
+	++resource->refs;
+}
+
+int
+resource_free(struct resource_table *resources, struct resource *resource)
+{
+	if (resource == NULL) {
+		return -1;
+	}
+
+	debug("Releasing resource with path \"%s\" and %d refs...",
+			resource->path, resource->refs);
+
+	if (--resource->refs == 0) {
+		debug("Freeing resource with path \"%s\"...", resource->path);
+		if (resource->prev == NULL) {
+			resources->head = resource->next;
+		} else {
+			resource->prev->next = resource->next;
+		}
+		if (resource->next == NULL) {
+			resources->tail = resource->prev;
+		} else {
+			resource->next->prev = resource->prev;
+		}
+		free(resource);
+		return 1;
+	}
+	return 0;
+}
--
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