perf: performance improvements (#107-#111)

src/client/scanner.h

@@ -5,6 +5,7 @@
 #include "queue.h"
 #include <dirent.h>
 #include <stdbool.h>
+#include <threads.h>
 
 typedef struct {
   Queue* directories;
@@ -20,6 +21,18 @@ typedef struct {
   unsigned long long min_size;
 } DirectoryScanner;
 
+typedef struct {
+  Queue* result_queue;
+  mtx_t result_mutex;
+  cnd_t result_not_empty;
+  cnd_t result_not_full;
+  int num_threads;
+  thrd_t* threads;
+  bool done;
+  int completed;
+  Chunk* initial_chunk;
+} ParallelScanner;
+
 DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metadata,
                                            unsigned long long chunk_size, char** exclude_patterns,
                                            int exclude_count, char** include_patterns,
@@ -28,4 +41,12 @@ DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metada
 Chunk* directory_scanner_next(DirectoryScanner* scanner);
 void directory_scanner_destroy(DirectoryScanner* scanner);
 
+ParallelScanner* parallel_scanner_create(char* root_directory, bool use_metadata,
+                                         unsigned long long chunk_size, char** exclude_patterns,
+                                         int exclude_count, char** include_patterns,
+                                         int include_count, unsigned long long max_size,
+                                         unsigned long long min_size, int num_threads);
+Chunk* parallel_scanner_next(ParallelScanner* scanner);
+void parallel_scanner_destroy(ParallelScanner* scanner);
+
 #endif