From 53bec0cfaef9ce8c646deee7d9ba6340137713a1 Mon Sep 17 00:00:00 2001
From: Uwe Hermann <uwe@hermann-uwe.de>
Date: Fri, 28 Jan 2011 00:11:00 +0100
Subject: [PATCH] libsigrokdecode: Always load all decoders upon init.

Let sigrokdecode_init() always load all decoders it can find in the
decoders directory, i.e., the user doesn't need to manually load decoders.
Instead he can just look up the list via sigrokdecode_list_decoders()
after sigrokdecode_init() has run.

This is not a problem, as sigrokdecode_init() is only run once per
sigrok-cli or sigrok-gui invocation, and even with many decoders this
should not take too long.

The list of decoders within libsigrokdecode is no longer a string, but
rather a list of 'struct sigrokdecode_decoder *' pointers.

Add sigrokdecode_get_decoder_by_id() API function which returns the
decoder with the specified ID (file name without ".py" suffix, for now),
or NULL if it cannot be found.

sigrokdecode_load_decoder() is now a private function and not exported
via the lib, i.e. not available to users of libsigrokdecode.
---
 decode.c       | 44 +++++++++++++++++++++++++++++++++++++++-----
 sigrokdecode.h |  2 +-
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/decode.c b/decode.c
index b1acff4..97a13c4 100644
--- a/decode.c
+++ b/decode.c
@@ -47,6 +47,9 @@ GSList *list_pds = NULL;
  *    Py_XDECREF()ing it (someone else will do it for you at some point).
  */
 
+static int sigrokdecode_load_decoder(const char *name,
+				     struct sigrokdecode_decoder **dec);
+
 /**
  * Initialize libsigrokdecode.
  *
@@ -56,7 +59,9 @@ int sigrokdecode_init(void)
 {
 	DIR *dir;
 	struct dirent *dp;
-	char *tmp;
+	char *decodername;
+	struct sigrokdecode_decoder *dec;
+	int ret;
 
 	/* Py_Initialize() returns void and usually cannot fail. */
 	Py_Initialize();
@@ -73,9 +78,18 @@ int sigrokdecode_init(void)
 	while ((dp = readdir(dir)) != NULL) {
 		if (!g_str_has_suffix(dp->d_name, ".py"))
 			continue;
-		/* For now use the filename (without .py) as decoder name. */
-		if ((tmp = g_strndup(dp->d_name, strlen(dp->d_name) - 3)))
-			list_pds = g_slist_append(list_pds, tmp);
+
+		/* Decoder name == filename (without .py suffix). */
+		decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3);
+
+		/* TODO: Error handling. */
+		dec = malloc(sizeof(struct sigrokdecode_decoder));
+
+		/* Load the decoder. */
+		ret = sigrokdecode_load_decoder(decodername, &dec);
+
+		/* Append it to the list of supported/loaded decoders. */
+		list_pds = g_slist_append(list_pds, dec);
 	}
 	closedir(dir);
 
@@ -94,6 +108,26 @@ GSList *sigrokdecode_list_decoders(void)
 	return list_pds;
 }
 
+/**
+ * Get the decoder with the specified ID.
+ *
+ * @param id The ID string of the decoder to return.
+ * @return The decoder with the specified ID, or NULL if not found.
+ */
+struct sigrokdecode_decoder *sigrokdecode_get_decoder_by_id(const char *id)
+{
+	GSList *l;
+	struct sigrokdecode_decoder *dec;
+
+	for (l = sigrokdecode_list_decoders(); l; l = l->next) {
+		dec = l->data;
+		if (!strcmp(dec->id, id))
+			return dec;
+	}
+
+	return NULL;
+}
+
 /**
  * Helper function to handle Python strings.
  *
@@ -153,7 +187,7 @@ err_h_decref_func:
  *
  * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise.
  */
-int sigrokdecode_load_decoder(const char *name,
+static int sigrokdecode_load_decoder(const char *name,
 			      struct sigrokdecode_decoder **dec)
 {
 	struct sigrokdecode_decoder *d;
diff --git a/sigrokdecode.h b/sigrokdecode.h
index 4876b5b..ede6d66 100644
--- a/sigrokdecode.h
+++ b/sigrokdecode.h
@@ -68,7 +68,7 @@ struct sigrokdecode_decoder {
 
 int sigrokdecode_init(void);
 GSList *sigrokdecode_list_decoders(void);
-int sigrokdecode_load_decoder(const char *name, struct sigrokdecode_decoder **dec);
+struct sigrokdecode_decoder *sigrokdecode_get_decoder_by_id(const char *id);
 int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec,
 			     uint8_t *inbuf, uint64_t inbuflen,
 			     uint8_t **outbuf, uint64_t *outbuflen);
-- 
2.30.2