commit 912767abf9ee5271061b35ec718f1d27482dbdbd
Author: Evan Klitzke <evan@eklitzke.org>
Date:   Sun Jul 1 23:40:49 2012 -0700

    add reader threads

diff --git a/src/index_reader.cc b/src/index_reader.cc
index adf7f27..f890b44 100644
--- a/src/index_reader.cc
+++ b/src/index_reader.cc
@@ -11,6 +11,7 @@
 #include <fstream>
 #include <iostream>
 #include <set>
+#include <thread>

 namespace codesearch {
 bool IndexReader::Verify() {
@@ -44,11 +45,15 @@ bool IndexReader::Initialize() {
 bool IndexReader::Search(const std::string &query,
                          SearchResults *results) {
   results->Reset();
+  std::vector<std::thread> threads;
   for (const auto &shard : shards_) {
-    if (!shard->Search(query, results)) {
-      results->Reset();
-      return false;
-    }
+    threads.push_back(std::thread(&ShardReader::Search, shard, query));
+  }
+
+  std::size_t i = 0;
+  for (const auto & shard : shards_) {
+    threads[i++].join();
+    results->Extend(shard->results());
   }
   return true;
 }
diff --git a/src/search_results.h b/src/search_results.h
index 0bb61d5..9f285c2 100644
--- a/src/search_results.h
+++ b/src/search_results.h
@@ -32,7 +32,13 @@ class SearchResults {
     SearchResult r(filename, line_num, line_text);
     results_.push_back(r);
   }
-  const std::vector<SearchResult> &results() const { return results_; };
+
+  void Extend(const SearchResults &other) {
+    const auto &other_results = other.results();
+    results_.insert(results_.end(), other_results.begin(), other_results.end());
+  }
+
+  const std::vector<SearchResult>& results() const { return results_; };
  private:
   std::vector<SearchResult> results_;
 };
diff --git a/src/shard_reader.cc b/src/shard_reader.cc
index 56bf1aa..1ac521f 100644
--- a/src/shard_reader.cc
+++ b/src/shard_reader.cc
@@ -7,13 +7,11 @@
 #include <algorithm>
 #include <iostream>
 #include <fstream>
-
 #include <set>

 #include <leveldb/cache.h>
 #include <leveldb/options.h>

-
 namespace codesearch {

 bool ShardReader::Initialize() {
@@ -48,7 +46,8 @@ bool ShardReader::Initialize() {
   return true;
 }

-bool ShardReader::Search(const std::string &query, SearchResults *results) {
+bool ShardReader::Search(const std::string &query) {
+  results_.Reset();
   if (query.size() < ngram_size_) {
     return true;
   }
@@ -105,13 +104,12 @@ bool ShardReader::Search(const std::string &query, SearchResults *results) {
       FileValue fileval;
       fileval.ParseFromString(value);

-      results->AddResult(fileval.filename(), pos.file_line(), pos_line);
+      results_.AddResult(fileval.filename(), pos.file_line(), pos_line);
     }
   }
   return true;
 }

-
 bool ShardReader::GetCandidates(const std::string &ngram,
                                 std::vector<std::uint64_t> *candidates) {
   assert(candidates->empty());
diff --git a/src/shard_reader.h b/src/shard_reader.h
index 11f398f..be4ba89 100644
--- a/src/shard_reader.h
+++ b/src/shard_reader.h
@@ -27,7 +27,10 @@ class ShardReader {
   bool Initialize();

   // Returns true on success, false on failure.
-  bool Search(const std::string &query, SearchResults *results);
+  bool Search(const std::string &query);
+
+  // Access the search results.
+  const SearchResults& results() const { return results_; }

   ~ShardReader();

@@ -40,6 +43,8 @@ class ShardReader {
   leveldb::DB* ngrams_db_;
   leveldb::DB* positions_db_;

+  SearchResults results_;
+
   bool GetCandidates(const std::string &ngram,
                      std::vector<std::uint64_t> *candidates);
 };