Backends API rework

backend.c

@@ -6,66 +6,47 @@
  * Author: Paul Cercueil <[email protected]>
  */
 
+#include "dynamic.h"
 #include "iio-config.h"
 #include "iio-private.h"
 
 #include <string.h>
 
-unsigned int iio_get_backends_count(void)
+unsigned int iio_get_builtin_backends_count(void)
 {
-	unsigned int count = 0;
+	unsigned int i, count = 0;
 
-	count += WITH_LOCAL_BACKEND;
-	count += WITH_XML_BACKEND;
-	count += WITH_NETWORK_BACKEND;
-	count += WITH_USB_BACKEND;
-	count += WITH_SERIAL_BACKEND;
+	for (i = 0; i < iio_backends_size; i++)
+		count += !!iio_backends[i];
 
 	return count;
 }
 
-const char * iio_get_backend(unsigned int index)
+const char * iio_get_builtin_backend(unsigned int index)
 {
-	if (WITH_LOCAL_BACKEND) {
-		if (index == 0)
-			return "local";
-		index--;
-	}
-
-	if (WITH_XML_BACKEND) {
-		if (index == 0)
-			return "xml";
-		index--;
-	}
-
-	if (WITH_NETWORK_BACKEND) {
-		if (index == 0)
-			return "ip";
-		index--;
-	}
+	unsigned int i;
 
-	if (WITH_USB_BACKEND) {
-		if (index == 0)
-			return "usb";
-		index--;
-	}
+	for (i = 0; i < iio_backends_size; i++) {
+		if (index == 0 && iio_backends[i])
+			return iio_backends[i]->name;
 
-	if (WITH_SERIAL_BACKEND) {
-		if (index == 0)
-			return "serial";
-		index --;
+		index -= !!iio_backends[i];
 	}
 
 	return NULL;
 }
 
-bool iio_has_backend(const char *backend)
+bool
+iio_has_backend(const struct iio_context_params *params, const char *backend)
 {
 	unsigned int i;
 
-	for (i = 0; i < iio_get_backends_count(); i++)
-		if (strcmp(backend, iio_get_backend(i)) == 0)
+	for (i = 0; i < iio_get_builtin_backends_count(); i++)
+		if (strcmp(backend, iio_get_builtin_backend(i)) == 0)
 			return true;
 
+	if (WITH_MODULES)
+		return iio_has_backend_dynamic(params, backend);
+
 	return false;
 }

compat.c

@@ -53,9 +53,9 @@ struct compat {
 	const char * (*iio_scan_get_uri)(const struct iio_scan *, size_t );
 
 	/* Backends */
-	bool (*iio_has_backend)(const char *);
-	unsigned int (*iio_get_backends_count)(void);
-	const char * (*iio_get_backend)(unsigned int);
+	bool (*iio_has_backend)(const struct iio_context_params *, const char *);
+	unsigned int (*iio_get_builtin_backends_count)(void);
+	const char * (*iio_get_builtin_backend)(unsigned int);
 
 	/* Context */
 	struct iio_context * (*iio_create_context)(const struct iio_context_params *,
@@ -1657,17 +1657,17 @@ void iio_library_get_version(unsigned int *major, unsigned int *minor,
 
 bool iio_has_backend(const char *backend)
 {
-	return IIO_CALL(iio_has_backend)(backend);
+	return IIO_CALL(iio_has_backend)(NULL, backend);
 }
 
 unsigned int iio_get_backends_count(void)
 {
-	return IIO_CALL(iio_get_backends_count)();
+	return IIO_CALL(iio_get_builtin_backends_count)();
 }
 
 const char * iio_get_backend(unsigned int index)
 {
-	return IIO_CALL(iio_get_backend)(index);
+	return IIO_CALL(iio_get_builtin_backend)(index);
 }
 
 void iio_strerror(int err, char *dst, size_t len)
@@ -1964,8 +1964,8 @@ static void compat_lib_init(void)
 	FIND_SYMBOL(ctx->lib, iio_scan_get_uri);
 
 	FIND_SYMBOL(ctx->lib, iio_has_backend);
-	FIND_SYMBOL(ctx->lib, iio_get_backends_count);
-	FIND_SYMBOL(ctx->lib, iio_get_backend);
+	FIND_SYMBOL(ctx->lib, iio_get_builtin_backends_count);
+	FIND_SYMBOL(ctx->lib, iio_get_builtin_backend);
 
 	FIND_SYMBOL(ctx->lib, iio_create_context);
 	FIND_SYMBOL(ctx->lib, iio_context_destroy);

context.c

@@ -406,7 +406,7 @@ int iio_context_set_timeout(struct iio_context *ctx, unsigned int timeout)
 	return 0;
 }
 
-const struct iio_backend *iio_backends[] = {
+const struct iio_backend * const iio_backends[] = {
 	IF_ENABLED(WITH_LOCAL_BACKEND, &iio_local_backend),
 	IF_ENABLED(WITH_NETWORK_BACKEND && !WITH_NETWORK_BACKEND_DYNAMIC,
 		   &iio_ip_backend),

dynamic.c

@@ -48,7 +48,7 @@ struct iio_module * iio_open_module(const struct iio_context_params *params,
 
 	module->lib = iio_dlopen(buf);
 	if (!module->lib) {
-		prm_err(params, "Unable to open plug-in\n");
+		prm_dbg(params, "Unable to open plug-in\n");
 		err = -ENOSYS;
 		goto err_free_name;
 	}
@@ -95,10 +95,8 @@ get_iio_backend(const struct iio_context_params *params,
 
 	lib = iio_open_module(params, name);
 	ret = iio_err(lib);
-	if (ret) {
-		prm_dbg(params, "Unable to open plug-in\n");
+	if (ret)
 		return iio_err_cast(lib);
-	}
 
 	backend = iio_module_get_backend(lib);
 	ret = iio_err(backend);
@@ -163,3 +161,18 @@ iio_create_dynamic_context(const struct iio_context_params *params,
 	iio_release_module(lib);
 	return iio_ptr(ret);
 }
+
+bool iio_has_backend_dynamic(const struct iio_context_params *params,
+			     const char *name)
+{
+	const struct iio_backend *backend;
+	struct iio_module *lib;
+	bool found;
+
+	backend = get_iio_backend(params, name, &lib);
+	found = !iio_err(backend);
+	if (found)
+		iio_release_module(lib);
+
+	return found;
+}

dynamic.h

@@ -9,8 +9,15 @@
 #ifndef __IIO_DYNAMIC_H
 #define __IIO_DYNAMIC_H
 
+#include <stdbool.h>
+
+struct iio_context_params;
+
 void * iio_dlopen(const char *path);
 void iio_dlclose(void *lib);
 void * iio_dlsym(void *lib, const char *symbol);
 
+bool iio_has_backend_dynamic(const struct iio_context_params *params,
+			     const char *name);
+
 #endif /* __IIO_DYNAMIC_H */

iio-private.h

@@ -246,7 +246,7 @@ extern const struct iio_backend iio_serial_backend;
 extern const struct iio_backend iio_usb_backend;
 extern const struct iio_backend iio_xml_backend;
 
-extern const struct iio_backend *iio_backends[];
+extern const struct iio_backend * const iio_backends[];
 extern const unsigned int iio_backends_size;
 
 ssize_t iio_xml_print_and_sanitized_param(char *ptr, ssize_t len,

include/iio/iio.h

@@ -396,27 +396,26 @@ __api void iio_strerror(int err, char *dst, size_t len);
 
 
 /** @brief Check if the specified backend is available
+ * @param params A pointer to a iio_context_params structure that contains
+ *   context creation information; can be NULL
  * @param backend The name of the backend to query
- * @return True if the backend is available, false otherwise
- *
- * Introduced in version 0.9. */
-__api __check_ret __cnst bool iio_has_backend(const char *backend);
+ * @return True if the backend is available, false otherwise */
+__api __check_ret bool
+iio_has_backend(const struct iio_context_params *params, const char *backend);
 
 
-/** @brief Get the number of available backends
- * @return The number of available backends
- *
- * Introduced in version 0.9. */
-__api __check_ret __cnst unsigned int iio_get_backends_count(void);
+/** @brief Get the number of available built-in backends
+ * @return The number of available built-in backends */
+__api __check_ret __cnst unsigned int
+iio_get_builtin_backends_count(void);
 
 
-/** @brief Retrieve the name of a given backend
- * @param index The index corresponding to the attribute
+/** @brief Retrieve the name of a given built-in backend
+ * @param index The index corresponding to the backend
  * @return On success, a pointer to a static NULL-terminated string
- * @return If the index is invalid, NULL is returned
- *
- * Introduced in version 0.9. */
-__api __check_ret __cnst const char * iio_get_backend(unsigned int index);
+ * @return If the index is invalid, NULL is returned */
+__api __check_ret __cnst const char *
+iio_get_builtin_backend(unsigned int index);
 
 
 /** @} *//* ------------------------------------------------------------------*/

utils/iio_common.c

@@ -432,8 +432,8 @@ void version(char *name)
 	       iio_context_get_version_major(NULL),
 	       iio_context_get_version_minor(NULL),
 	       iio_context_get_version_tag(NULL));
-        for (i = 0; i < iio_get_backends_count(); i++)
-                printf(" %s", iio_get_backend(i));
+        for (i = 0; i < iio_get_builtin_backends_count(); i++)
+                printf(" %s", iio_get_builtin_backend(i));
         printf("\n");
 }