Add more documentation.

This adds documentation of load_afd(), aft_init(), enum play_mode, and enum
afs_server_code.

diff --git a/afs.h b/afs.h
index aeaf8fb8189535ec44dbcd14d19f472b710f81d7..b89ba6181a09653bcbbafc6f6ef6606a723b4efe 100644 (file)
--- a/afs.h
+++ b/afs.h
@@ -97,7 +97,13 @@ struct afs_table {
                void *data);
 };
 
-enum play_mode {PLAY_MODE_MOOD, PLAY_MODE_PLAYLIST};
+/** How audio files are selected by afs. */
+enum play_mode {
+       /** Admissible files are determined by a mood definition. */
+       PLAY_MODE_MOOD,
+       /** All listed files are admissible. */
+       PLAY_MODE_PLAYLIST,
+};
 
 /**
  * Data about one audio file.
@@ -125,10 +131,25 @@ struct audio_file_data {
        struct afh_info afhi;
 };
 
+/**
+ * Codes used for communication between the server and the afs process.
+ *
+ * Before forking the afs child, para_server creates a bidirectional pipe
+ * through which both processes communicate. Usually para_server requests a new
+ * audio in order to start streaming or when the end of the current audio file
+ * has been reached.  The afs process responds to such a request by sending
+ * back an eight byte buffer. The first four bytes is the uint32_t
+ * representation of the code, usually \p NEXT_AUDIO_FILE if an admissible
+ * audio file was found, successfully opened and verified. The other four bytes
+ * represent the shared memory id of the shared memory area that contains
+ * details about the audio file to be streamed next. The open file descriptor
+ * of that file is also passed from afs to para_server through the same pipe.
+ */
 enum afs_server_code {
+       /** An audio file was successfully opened. */
        NEXT_AUDIO_FILE,
+       /** No admissible audio file was found. */
        NO_ADMISSIBLE_FILES,
-       AFD_CHANGE
 };
 
 /** Flags passed to for_each_matching_row(). */

diff --git a/aft.c b/aft.c
index 39e94a945e0b9b8c47d29e6bb59d799491f2f9e4..103373493f8cdadc8a6c5a640041f7453ef1fc30 100644 (file)
--- a/aft.c
+++ b/aft.c
@@ -652,6 +652,18 @@ err:
        return ret;
 }
 
+/**
+ * Extract a afd stored in a shared memory area.
+ *
+ * Attach the shared memory area given by \a shmid, load the audio file data
+ * stored therein and detach the area afterwards.  Called by vss, after
+ * receiving a positive response to the request for the next audio file.
+ +
+ * \param shmid The identifier of the shared memory area containing the afd.
+ * \param afd Result pointer.
+ *
+ * \return Standard.
+ */
 int load_afd(int shmid, struct audio_file_data *afd)
 {
        void *shm_afd;
@@ -2610,6 +2622,11 @@ static int aft_event_handler(enum afs_events event, struct para_buffer *pb,
        }
 }
 
+/**
+ * Initialize the audio file table.
+ *
+ * \param t Pointer to the structure to be initialized.
+ */
 void aft_init(struct afs_table *t)
 {
        t->open = aft_open;