input: Introduce new input module API.

[libsigrok.git] / src / libsigrok-internal.h

diff --git a/src/libsigrok-internal.h b/src/libsigrok-internal.h
index a18ccf6ae47787a7858d687f6ded1aadcdb0d080..0214fffbb6492b9e47d9652e9dda7393a9e0136c 100644 (file)
--- a/src/libsigrok-internal.h
+++ b/src/libsigrok-internal.h
@@ -143,6 +143,15 @@
        libusb_handle_events_timeout(ctx, tv)
 #endif
 
+/* Static definitions of structs ending with an all-zero entry are a
+ * problem when compiling with -Wmissing-field-initializers: GCC
+ * suppresses the warning only with { 0 }, clang wants { } */
+#ifdef __clang__
+#define ALL_ZERO { }
+#else
+#define ALL_ZERO { 0 }
+#endif
+
 struct sr_context {
 #ifdef HAVE_LIBUSB_1_0
        libusb_context *libusb_ctx;
@@ -159,6 +168,117 @@ struct sr_context {
 #endif
 };
 
+/** Input (file) module struct. */
+struct sr_input {
+       /**
+        * A pointer to this input module's 'struct sr_input_module'.
+        */
+       const struct sr_input_module *module;
+       GString *buf;
+       struct sr_dev_inst *sdi;
+       void *priv;
+};
+
+/** Input (file) module driver. */
+struct sr_input_module {
+       /**
+        * A unique ID for this output module, suitable for use in command-line
+        * clients, [a-z0-9-]. Must not be NULL.
+        */
+       const char *id;
+
+       /**
+        * A unique name for this output module, suitable for use in GUI
+        * clients, can contain UTF-8. Must not be NULL.
+        */
+       const char *name;
+
+       /**
+        * A short description of the output module. Must not be NULL.
+        *
+        * This can be displayed by frontends, e.g. when selecting the output
+        * module for saving a file.
+        */
+       const char *desc;
+
+       /**
+        * Zero-terminated list of metadata items the module needs to be able
+        * to identify an input stream. Can be all-zero, if the module cannot
+        * identify streams at all, i.e. has to be forced into use.
+        *
+        * Each item is one of:
+        *   SR_INPUT_META_FILENAME
+        *   SR_INPUT_META_FILESIZE
+        *   SR_INPUT_META_HEADER
+        *   SR_INPUT_META_MIMETYPE
+        *
+        * If the high bit (SR_INPUT META_REQUIRED) is set, the module cannot
+        * identify a stream without the given metadata.
+        */
+       const uint8_t metadata[8];
+
+       /**
+        * Returns a NULL-terminated list of options this module can take.
+        * Can be NULL, if the module has no options.
+        */
+       struct sr_option *(*options) (void);
+
+       /**
+        * Check if this input module can load and parse the specified stream.
+        *
+        * @param[in] metadata Metadata the module can use to identify the stream.
+        *
+        * @retval TRUE This module knows the format.
+        * @retval FALSE This module does not know the format.
+        */
+       int (*format_match) (GHashTable *metadata);
+
+       /**
+        * Initialize the input module.
+        *
+        * @param in A pointer to a valid 'struct sr_input' that the caller
+        *           has to allocate and provide to this function. It is also
+        *           the responsibility of the caller to free it later.
+        * @param[in] filename The name (and path) of the file to use.
+        *
+        * @retval SR_OK Success
+        * @retval other Negative error code.
+        */
+       int (*init) (struct sr_input *in, GHashTable *options);
+
+       /**
+        * Load a file, parsing the input according to the file's format.
+        *
+        * This function will send datafeed packets to the session bus, so
+        * the calling frontend must have registered its session callbacks
+        * beforehand.
+        *
+        * The packet types sent across the session bus by this function must
+        * include at least SR_DF_HEADER, SR_DF_END, and an appropriate data
+        * type such as SR_DF_LOGIC. It may also send a SR_DF_TRIGGER packet
+        * if appropriate.
+        *
+        * @param in A pointer to a valid 'struct sr_input' that the caller
+        *           has to allocate and provide to this function. It is also
+        *           the responsibility of the caller to free it later.
+        * @param f The name (and path) of the file to use.
+        *
+        * @retval SR_OK Success
+        * @retval other Negative error code.
+        */
+       int (*receive) (const struct sr_input *in, GString *buf);
+
+       /**
+        * This function is called after the caller is finished using
+        * the input module, and can be used to free any internal
+        * resources the module may keep.
+        *
+        * @retval SR_OK Success
+        * @retval other Negative error code.
+        */
+       int (*cleanup) (struct sr_input *in);
+};
+
 /** Output module instance. */
 struct sr_output {
        /** A pointer to this output's module.  */
@@ -205,11 +325,8 @@ struct sr_output_module {
        /**
         * Returns a NULL-terminated list of options this module can take.
         * Can be NULL, if the module has no options.
-        *
-        * If cached is TRUE, no new GVariants are created for the def and
-        * values fields; instead, the current values are returned.
         */
-       struct sr_option *(*options) (gboolean cached);
+       const struct sr_option *(*options) (void);
 
        /**
         * This function is called once, at the beginning of an output stream.