input: add confidence (detection strength) to format_match()

[libsigrok.git] / src / input / input.c

diff --git a/src/input/input.c b/src/input/input.c
index 18a4b639ed5160e122e046bed5b44a463fe3ed96..48660d379b9b6e69fde4546cbe8f91a7a67669b9 100644 (file)
--- a/src/input/input.c
+++ b/src/input/input.c
@@ -342,7 +342,9 @@ static gboolean check_required_metadata(const uint8_t *metadata, uint8_t *avail)
  * 128 bytes is normally enough.
  *
  * If an input module is found, an instance is created into *in.
- * Otherwise, *in contains NULL.
+ * Otherwise, *in contains NULL. When multiple input moduless claim
+ * support for the format, the one with highest confidence takes
+ * precedence. Applications will see at most one input module spec.
  *
  * If an instance is created, it has the given buffer used for scanning
  * already submitted to it, to be processed before more data is sent.
@@ -353,9 +355,10 @@ static gboolean check_required_metadata(const uint8_t *metadata, uint8_t *avail)
  */
 SR_API int sr_input_scan_buffer(GString *buf, const struct sr_input **in)
 {
-       const struct sr_input_module *imod;
+       const struct sr_input_module *imod, *best_imod;
        GHashTable *meta;
        unsigned int m, i;
+       unsigned int conf, best_conf;
        int ret;
        uint8_t mitem, avail_metadata[8];
 
@@ -364,7 +367,8 @@ SR_API int sr_input_scan_buffer(GString *buf, const struct sr_input **in)
        avail_metadata[1] = 0;
 
        *in = NULL;
-       ret = SR_ERR;
+       best_imod = NULL;
+       best_conf = ~0;
        for (i = 0; input_module_list[i]; i++) {
                imod = input_module_list[i];
                if (!imod->metadata[0]) {
@@ -388,45 +392,55 @@ SR_API int sr_input_scan_buffer(GString *buf, const struct sr_input **in)
                        continue;
                }
                sr_spew("Trying module %s.", imod->id);
-               ret = imod->format_match(meta);
+               ret = imod->format_match(meta, &conf);
                g_hash_table_destroy(meta);
                if (ret == SR_ERR_DATA) {
                        /* Module recognized this buffer, but cannot handle it. */
-                       break;
+                       continue;
                } else if (ret == SR_ERR) {
                        /* Module didn't recognize this buffer. */
                        continue;
                } else if (ret != SR_OK) {
                        /* Can be SR_ERR_NA. */
-                       return ret;
+                       continue;
                }
 
                /* Found a matching module. */
-               sr_spew("Module %s matched.", imod->id);
-               *in = sr_input_new(imod, NULL);
+               sr_spew("Module %s matched, confidence %u.", imod->id, conf);
+               if (conf >= best_conf)
+                       continue;
+               best_imod = imod;
+               best_conf = conf;
+       }
+
+       if (best_imod) {
+               *in = sr_input_new(best_imod, NULL);
                g_string_insert_len((*in)->buf, 0, buf->str, buf->len);
-               break;
+               return SR_OK;
        }
 
-       return ret;
+       return SR_ERR;
 }
 
 /**
  * Try to find an input module that can parse the given file.
  *
  * If an input module is found, an instance is created into *in.
- * Otherwise, *in contains NULL.
+ * Otherwise, *in contains NULL. When multiple input moduless claim
+ * support for the format, the one with highest confidence takes
+ * precedence. Applications will see at most one input module spec.
  *
  */
 SR_API int sr_input_scan_file(const char *filename, const struct sr_input **in)
 {
        int64_t filesize;
        FILE *stream;
-       const struct sr_input_module *imod;
+       const struct sr_input_module *imod, *best_imod;
        GHashTable *meta;
        GString *header;
        size_t count;
        unsigned int midx, i;
+       unsigned int conf, best_conf;
        int ret;
        uint8_t avail_metadata[8];
 
@@ -475,8 +489,8 @@ SR_API int sr_input_scan_file(const char *filename, const struct sr_input **in)
        avail_metadata[midx] = 0;
        /* TODO: MIME type */
 
-       ret = SR_ERR;
-
+       best_imod = NULL;
+       best_conf = ~0;
        for (i = 0; input_module_list[i]; i++) {
                imod = input_module_list[i];
                if (!imod->metadata[0]) {
@@ -490,24 +504,30 @@ SR_API int sr_input_scan_file(const char *filename, const struct sr_input **in)
 
                sr_dbg("Trying module %s.", imod->id);
 
-               ret = imod->format_match(meta);
+               ret = imod->format_match(meta, &conf);
                if (ret == SR_ERR) {
                        /* Module didn't recognize this buffer. */
                        continue;
                } else if (ret != SR_OK) {
                        /* Module recognized this buffer, but cannot handle it. */
-                       break;
+                       continue;
                }
                /* Found a matching module. */
-               sr_dbg("Module %s matched.", imod->id);
-
-               *in = sr_input_new(imod, NULL);
-               break;
+               sr_dbg("Module %s matched, confidence %u.", imod->id, conf);
+               if (conf >= best_conf)
+                       continue;
+               best_imod = imod;
+               best_conf = conf;
        }
        g_hash_table_destroy(meta);
        g_string_free(header, TRUE);
 
-       return ret;
+       if (best_imod) {
+               *in = sr_input_new(best_imod, NULL);
+               return SR_OK;
+       }
+
+       return SR_ERR;
 }
 
 /**