#define LOG_PREFIX "input"
/** @endcond */
+#define CHUNK_SIZE (4 * 1024 * 1024)
+
/**
* @file
*
* Try to find an input module that can parse the given buffer.
*
* The buffer must contain enough of the beginning of the file for
- * the input modules to find a match. This is format-dependent, but
- * 128 bytes is normally enough.
+ * the input modules to find a match. This is format-dependent. When
+ * magic strings get checked, 128 bytes normally could be enough. Note
+ * that some formats try to parse larger header sections, and benefit
+ * from seeing a larger scope.
*
* If an input module is found, an instance is created into *in.
* Otherwise, *in contains NULL. When multiple input moduless claim
fclose(stream);
return SR_ERR;
}
- /* This actually allocates 256 bytes to allow for NUL termination. */
- header = g_string_sized_new(255);
+ header = g_string_sized_new(CHUNK_SIZE);
count = fread(header->str, 1, header->allocated_len - 1, stream);
-
- if (count != header->allocated_len - 1 && ferror(stream)) {
+ if (count < 1 || ferror(stream)) {
sr_err("Failed to read %s: %s", filename, g_strerror(errno));
fclose(stream);
g_string_free(header, TRUE);
return SR_ERR;
}
+/**
+ * Return the input instance's module "class". This can be used to find out
+ * which input module handles a specific input file. This is especially
+ * useful when an application did not create the input stream by specifying
+ * an input module, but instead some shortcut or convenience wrapper did.
+ *
+ * @since 0.6.0
+ */
+SR_API const struct sr_input_module *sr_input_module_get(const struct sr_input *in)
+{
+ if (!in)
+ return NULL;
+
+ return in->module;
+}
+
/**
* Return the input instance's (virtual) device instance. This can be
* used to find out the number of channels and other information.
*
* @since 0.5.0
*/
-SR_API int sr_input_reset(const struct sr_input *in)
+SR_API int sr_input_reset(const struct sr_input *in_ro)
{
- if (!in->module->reset) {
+ struct sr_input *in;
+ int rc;
+
+ in = (struct sr_input *)in_ro; /* "un-const" */
+ if (!in || !in->module)
+ return SR_ERR_ARG;
+
+ /*
+ * Run the optional input module's .reset() method. This shall
+ * take care of the context (kept in the 'inc' variable).
+ */
+ if (in->module->reset) {
+ sr_spew("Resetting %s module.", in->module->id);
+ rc = in->module->reset(in);
+ } else {
sr_spew("Tried to reset %s module but no reset handler found.",
in->module->id);
- return SR_OK;
+ rc = SR_OK;
}
- sr_spew("Resetting %s module.", in->module->id);
- return in->module->reset((struct sr_input *)in);
+ /*
+ * Handle input module status (kept in the 'in' variable) here
+ * in common logic. This agrees with how input module's receive()
+ * and end() routines "amend but never seed" the 'in' information.
+ *
+ * Void potentially accumulated receive() buffer content, and
+ * clear the sdi_ready flag. This makes sure that subsequent
+ * processing will scan the header again before sample data gets
+ * interpreted, and stale content from previous calls won't affect
+ * the result.
+ *
+ * This common logic does not harm when the input module implements
+ * .reset() and contains identical assignments. In the absence of
+ * an individual .reset() method, simple input modules can completely
+ * rely on common code and keep working across resets.
+ */
+ if (in->buf)
+ g_string_truncate(in->buf, 0);
+ in->sdi_ready = FALSE;
+
+ return rc;
}
/**
if (!in)
return;
+ /*
+ * Run the input module's optional .cleanup() routine. This
+ * takes care of the context (kept in the 'inc' variable).
+ */
if (in->module->cleanup)
in->module->cleanup((struct sr_input *)in);
+
+ /*
+ * Common code releases the input module's state (kept in the
+ * 'in' variable). Release the device instance, the receive()
+ * buffer, the shallow 'in->priv' block which is 'inc' (after
+ * .cleanup() released potentially nested resources under 'inc').
+ */
sr_dev_inst_free(in->sdi);
if (in->buf->len > 64) {
/* That seems more than just some sub-unitsize leftover... */