Various improvements: Toolbox, Updater and Unit Tests. (#2250)

* Toolbox: add seek to character stream method. UpdateUtils: reverse manifest iterator. UnitTests: more unit tests.
* Target: bump API version. Updater: delete empty folders from manifest before resource deployment.
* UnitTests: use manifest from unit_tests folder instead of global one
* Make PVS happy
* sector cache: allocate always
* Better PVS config for manifest.c
* PVS: Move exception outside of condition
* PVS: remove confusing condition

Co-authored-by: SG <who.just.the.doctor@gmail.com>

lib/update_util/resources/manifest.c

@@ -60,6 +60,12 @@ ResourceManifestEntry* resource_manifest_reader_next(ResourceManifestReader* res
 
         char type_code = furi_string_get_char(resource_manifest->linebuf, 0);
         switch(type_code) {
+        case 'V':
+            resource_manifest->entry.type = ResourceManifestEntryTypeVersion;
+            break;
+        case 'T':
+            resource_manifest->entry.type = ResourceManifestEntryTypeTimestamp;
+            break;
         case 'F':
             resource_manifest->entry.type = ResourceManifestEntryTypeFile;
             break;
@@ -98,9 +104,9 @@ ResourceManifestEntry* resource_manifest_reader_next(ResourceManifestReader* res
             furi_string_right(resource_manifest->linebuf, offs + 1);
 
             furi_string_set(resource_manifest->entry.name, resource_manifest->linebuf);
-        } else if(resource_manifest->entry.type == ResourceManifestEntryTypeDirectory) { //-V547
-            /* Parse directory entry
-               D:<name> */
+        } else { //-V547
+            /* Everything else is plain key value. Parse version, timestamp or directory entry
+               <Type>:<Value> */
 
             /* Remove entry type code */
             furi_string_right(resource_manifest->linebuf, 2);
@@ -113,3 +119,45 @@ ResourceManifestEntry* resource_manifest_reader_next(ResourceManifestReader* res
 
     return NULL;
 }
+
+ResourceManifestEntry*
+    resource_manifest_reader_previous(ResourceManifestReader* resource_manifest) {
+    furi_assert(resource_manifest);
+
+    // Snapshot position for rollback
+    const size_t previous_position = stream_tell(resource_manifest->stream);
+
+    // We need to jump 2 lines back
+    size_t jumps = 2;
+    // Special case: end of the file.
+    const bool was_eof = stream_eof(resource_manifest->stream);
+    if(was_eof) {
+        jumps = 1;
+    }
+    while(jumps) {
+        if(!stream_seek_to_char(resource_manifest->stream, '\n', StreamDirectionBackward)) {
+            break;
+        }
+        if(stream_tell(resource_manifest->stream) < (previous_position - 1)) {
+            jumps--;
+        }
+    }
+
+    // Special case: first line. Force seek to zero
+    if(jumps == 1) {
+        jumps = 0;
+        stream_seek(resource_manifest->stream, 0, StreamOffsetFromStart);
+    }
+
+    if(jumps == 0) {
+        ResourceManifestEntry* entry = resource_manifest_reader_next(resource_manifest);
+        // Special case: was end of the file, prevent loop
+        if(was_eof) {
+            stream_seek(resource_manifest->stream, -1, StreamOffsetFromCurrent);
+        }
+        return entry;
+    } else {
+        stream_seek(resource_manifest->stream, previous_position, StreamOffsetFromStart);
+        return NULL;
+    }
+}

lib/update_util/resources/manifest.h

@@ -11,6 +11,8 @@ extern "C" {
 
 typedef enum {
     ResourceManifestEntryTypeUnknown = 0,
+    ResourceManifestEntryTypeVersion,
+    ResourceManifestEntryTypeTimestamp,
     ResourceManifestEntryTypeDirectory,
     ResourceManifestEntryTypeFile,
 } ResourceManifestEntryType;
@@ -52,6 +54,18 @@ bool resource_manifest_reader_open(ResourceManifestReader* resource_manifest, co
  */
 ResourceManifestEntry* resource_manifest_reader_next(ResourceManifestReader* resource_manifest);
 
+/** Read previous file/dir entry from manifest
+ *
+ * You must be at the end of the manifest to use this function.
+ * Intended to be used after reaching end with resource_manifest_reader_next
+ *
+ * @param      resource_manifest  Pointer to the ResourceManifestReader instance
+ *
+ * @return     entry or NULL if end of file
+ */
+ResourceManifestEntry*
+    resource_manifest_reader_previous(ResourceManifestReader* resource_manifest);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif