--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2015 Daniel Elstner <daniel.kitta@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <errno.h>
+#include <stdio.h>
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+
+/** @cond PRIVATE */
+#define LOG_PREFIX "resource"
+/** @endcond */
+
+/**
+ * @file
+ *
+ * Access to resource files.
+ */
+
+static FILE *try_open_file(const char *datadir, const char *subdir,
+ const char *name)
+{
+ char *filename;
+ FILE *file;
+
+ filename = g_build_filename(datadir, subdir, name, NULL);
+ file = g_fopen(filename, "rb");
+
+ if (file)
+ sr_info("Opened '%s'.", filename);
+ else
+ sr_spew("Attempt to open '%s' failed: %s",
+ filename, g_strerror(errno));
+ g_free(filename);
+
+ return file;
+}
+
+static int resource_open_default(struct sr_resource *res,
+ const char *name, void *cb_data)
+{
+ int64_t filesize;
+ const char *builtindir, *subdir;
+ const char *const *datadirs;
+ FILE *file;
+
+ (void)cb_data;
+
+ switch (res->type) {
+ case SR_RESOURCE_FIRMWARE:
+ builtindir = FIRMWARE_DIR;
+ subdir = "sigrok-firmware";
+ break;
+ default:
+ sr_err("%s: unknown type %d.", __func__, res->type);
+ return SR_ERR_ARG;
+ }
+
+ file = try_open_file(g_get_user_data_dir(), subdir, name);
+ /*
+ * Scan the hard-coded directory before the system directories to
+ * avoid picking up possibly outdated files from a system install.
+ */
+ if (!file)
+ file = try_open_file(builtindir, "", name);
+
+ if (!file) {
+ datadirs = g_get_system_data_dirs();
+ while (*datadirs && !file)
+ file = try_open_file(*datadirs++, subdir, name);
+ }
+ if (!file) {
+ sr_err("Failed to locate '%s'.", name);
+ return SR_ERR;
+ }
+
+ filesize = sr_file_get_size(file);
+ if (filesize < 0) {
+ sr_err("Failed to obtain size of '%s': %s",
+ name, g_strerror(errno));
+ fclose(file);
+ return SR_ERR;
+ }
+ res->size = filesize;
+ res->handle = file;
+
+ return SR_OK;
+}
+
+static int resource_close_default(struct sr_resource *res, void *cb_data)
+{
+ FILE *file;
+
+ (void)cb_data;
+
+ file = res->handle;
+ if (!file) {
+ sr_err("%s: invalid handle.", __func__);
+ return SR_ERR_ARG;
+ }
+
+ if (fclose(file) < 0) {
+ sr_err("Failed to close file: %s", g_strerror(errno));
+ return SR_ERR;
+ }
+ res->handle = NULL;
+
+ return SR_OK;
+}
+
+static ssize_t resource_read_default(const struct sr_resource *res,
+ void *buf, size_t count, void *cb_data)
+{
+ FILE *file;
+ size_t n_read;
+
+ (void)cb_data;
+
+ file = res->handle;
+ if (!file) {
+ sr_err("%s: invalid handle.", __func__);
+ return SR_ERR_ARG;
+ }
+ if (count > SSIZE_MAX) {
+ sr_err("%s: count %zu too large.", __func__, count);
+ return SR_ERR_ARG;
+ }
+
+ n_read = fread(buf, 1, count, file);
+
+ if (n_read != count && ferror(file)) {
+ sr_err("Failed to read resource file: %s", g_strerror(errno));
+ return SR_ERR;
+ }
+ return n_read;
+}
+
+/**
+ * Install resource access hooks.
+ *
+ * @param ctx libsigrok context. Must not be NULL.
+ * @param open_cb Resource open callback, or NULL to unset.
+ * @param close_cb Resource close callback, or NULL to unset.
+ * @param read_cb Resource read callback, or NULL to unset.
+ * @param cb_data User data pointer passed to callbacks.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
+ *
+ * @since 0.4.0
+ */
+SR_API int sr_resource_set_hooks(struct sr_context *ctx,
+ sr_resource_open_callback open_cb,
+ sr_resource_close_callback close_cb,
+ sr_resource_read_callback read_cb, void *cb_data)
+{
+ if (!ctx) {
+ sr_err("%s: ctx was NULL.", __func__);
+ return SR_ERR_ARG;
+ }
+ if (open_cb && close_cb && read_cb) {
+ ctx->resource_open_cb = open_cb;
+ ctx->resource_close_cb = close_cb;
+ ctx->resource_read_cb = read_cb;
+ ctx->resource_cb_data = cb_data;
+ } else if (!open_cb && !close_cb && !read_cb) {
+ ctx->resource_open_cb = &resource_open_default;
+ ctx->resource_close_cb = &resource_close_default;
+ ctx->resource_read_cb = &resource_read_default;
+ ctx->resource_cb_data = ctx;
+ } else {
+ sr_err("%s: inconsistent callback pointers.", __func__);
+ return SR_ERR_ARG;
+ }
+ return SR_OK;
+}
+
+/**
+ * Open resource.
+ *
+ * @param ctx libsigrok context. Must not be NULL.
+ * @param[out] res Resource descriptor to fill in. Must not be NULL.
+ * @param type Resource type ID.
+ * @param name Name of the resource. Must not be NULL.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
+ * @retval SR_ERR Other error.
+ *
+ * @private
+ */
+SR_PRIV int sr_resource_open(struct sr_context *ctx,
+ struct sr_resource *res, int type, const char *name)
+{
+ int ret;
+
+ res->size = 0;
+ res->handle = NULL;
+ res->type = type;
+
+ ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data);
+
+ if (ret != SR_OK)
+ sr_err("Failed to open resource '%s'.", name);
+
+ return ret;
+}
+
+/**
+ * Close resource.
+ *
+ * @param ctx libsigrok context. Must not be NULL.
+ * @param[inout] res Resource descriptor. Must not be NULL.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
+ * @retval SR_ERR Other error.
+ *
+ * @private
+ */
+SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res)
+{
+ int ret;
+
+ ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data);
+
+ if (ret != SR_OK)
+ sr_err("Failed to close resource.");
+
+ return ret;
+}
+
+/**
+ * Read resource data.
+ *
+ * @param ctx libsigrok context. Must not be NULL.
+ * @param[in] res Resource descriptor. Must not be NULL.
+ * @param[out] buf Buffer to store @a count bytes into. Must not be NULL.
+ * @param count Number of bytes to read.
+ *
+ * @return The number of bytes actually read, or a negative value on error.
+ * @retval SR_ERR_ARG Invalid argument.
+ * @retval SR_ERR Other error.
+ *
+ * @private
+ */
+SR_PRIV ssize_t sr_resource_read(struct sr_context *ctx,
+ const struct sr_resource *res, void *buf, size_t count)
+{
+ ssize_t n_read;
+
+ n_read = (*ctx->resource_read_cb)(res, buf, count,
+ ctx->resource_cb_data);
+ if (n_read < 0)
+ sr_err("Failed to read resource.");
+
+ return n_read;
+}
+
+/**
+ * Load a resource into memory.
+ *
+ * @param ctx libsigrok context. Must not be NULL.
+ * @param type Resource type ID.
+ * @param name Name of the resource. Must not be NULL.
+ * @param[out] size Size in bytes of the returned buffer. Must not be NULL.
+ * @param max_size Size limit. Error out if the resource is larger than this.
+ *
+ * @return A buffer containing the resource data, or NULL on failure. Must
+ * be freed by the caller using g_free().
+ *
+ * @private
+ */
+SR_PRIV void *sr_resource_load(struct sr_context *ctx,
+ int type, const char *name, size_t *size, size_t max_size)
+{
+ struct sr_resource res;
+ void *buf;
+ ssize_t n_read;
+
+ if (sr_resource_open(ctx, &res, type, name) != SR_OK)
+ return NULL;
+
+ if (res.size > max_size) {
+ sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.",
+ res.size, name, max_size);
+ sr_resource_close(ctx, &res);
+ return NULL;
+ }
+ buf = g_try_malloc(res.size);
+ if (!buf) {
+ sr_err("Failed to allocate buffer for '%s'.", name);
+ sr_resource_close(ctx, &res);
+ return NULL;
+ }
+
+ n_read = sr_resource_read(ctx, &res, buf, res.size);
+ sr_resource_close(ctx, &res);
+
+ if (n_read < 0 || (size_t)n_read != res.size) {
+ if (n_read >= 0)
+ sr_err("Failed to read '%s': premature end of file.",
+ name);
+ g_free(buf);
+ return NULL;
+ }
+
+ *size = res.size;
+ return buf;
+}
+
+/** @} */
projects / libsigrok.git / commitdiff