From afb86638cdd3026cd7ca1ecbb83111d1aff2f727 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 15 Apr 2016 15:39:20 +0200
Subject: [PATCH] Updates for negative .narinfo caching

---
 src/hydra-queue-runner/hydra-queue-runner.cc  |  1 +
 .../s3-binary-cache-store.cc                  | 36 +++++++++++--------
 .../s3-binary-cache-store.hh                  |  2 +-
 3 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/src/hydra-queue-runner/hydra-queue-runner.cc b/src/hydra-queue-runner/hydra-queue-runner.cc
index 6aec8adc..2dac0dbd 100644
--- a/src/hydra-queue-runner/hydra-queue-runner.cc
+++ b/src/hydra-queue-runner/hydra-queue-runner.cc
@@ -639,6 +639,7 @@ void State::dumpStatus(Connection & conn, bool log)
             auto & stats = store->getStats();
             nested.attr("narInfoRead", stats.narInfoRead);
             nested.attr("narInfoReadAverted", stats.narInfoReadAverted);
+            nested.attr("narInfoMissing", stats.narInfoMissing);
             nested.attr("narInfoWrite", stats.narInfoWrite);
             nested.attr("narInfoCacheSize", stats.narInfoCacheSize);
             nested.attr("narRead", stats.narRead);
diff --git a/src/hydra-queue-runner/s3-binary-cache-store.cc b/src/hydra-queue-runner/s3-binary-cache-store.cc
index ca19fe10..05726f4e 100644
--- a/src/hydra-queue-runner/s3-binary-cache-store.cc
+++ b/src/hydra-queue-runner/s3-binary-cache-store.cc
@@ -87,9 +87,8 @@ bool S3BinaryCacheStore::isValidPath(const Path & storePath)
     try {
         readNarInfo(storePath);
         return true;
-    } catch (S3Error & e) {
-        if (e.err == Aws::S3::S3Errors::NO_SUCH_KEY) return false;
-        throw;
+    } catch (InvalidPath & e) {
+        return false;
     }
 }
 
@@ -142,7 +141,7 @@ void S3BinaryCacheStore::upsertFile(const std::string & path, const std::string
     stats.putTimeMs += duration;
 }
 
-std::string S3BinaryCacheStore::getFile(const std::string & path)
+std::shared_ptr<std::string> S3BinaryCacheStore::getFile(const std::string & path)
 {
     printMsg(lvlDebug, format("fetching ‘s3://%1%/%2%’...") % bucketName % path);
 
@@ -157,24 +156,31 @@ std::string S3BinaryCacheStore::getFile(const std::string & path)
 
     stats.get++;
 
-    auto now1 = std::chrono::steady_clock::now();
+    try {
 
-    auto result = checkAws(format("AWS error fetching ‘%s’") % path,
-        client->GetObject(request));
+        auto now1 = std::chrono::steady_clock::now();
 
-    auto now2 = std::chrono::steady_clock::now();
+        auto result = checkAws(format("AWS error fetching ‘%s’") % path,
+            client->GetObject(request));
 
-    auto res = dynamic_cast<std::stringstream &>(result.GetBody()).str();
+        auto now2 = std::chrono::steady_clock::now();
 
-    auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
+        auto res = dynamic_cast<std::stringstream &>(result.GetBody()).str();
 
-    printMsg(lvlTalkative, format("downloaded ‘s3://%1%/%2%’ (%3% bytes) in %4% ms")
-        % bucketName % path % res.size() % duration);
+        auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
 
-    stats.getBytes += res.size();
-    stats.getTimeMs += duration;
+        printMsg(lvlTalkative, format("downloaded ‘s3://%1%/%2%’ (%3% bytes) in %4% ms")
+            % bucketName % path % res.size() % duration);
 
-    return res;
+        stats.getBytes += res.size();
+        stats.getTimeMs += duration;
+
+        return std::make_shared<std::string>(res);
+
+    } catch (S3Error & e) {
+        if (e.err == Aws::S3::S3Errors::NO_SUCH_KEY) return 0;
+        throw;
+    }
 }
 
 }
diff --git a/src/hydra-queue-runner/s3-binary-cache-store.hh b/src/hydra-queue-runner/s3-binary-cache-store.hh
index d1b9f6dc..b8d7a370 100644
--- a/src/hydra-queue-runner/s3-binary-cache-store.hh
+++ b/src/hydra-queue-runner/s3-binary-cache-store.hh
@@ -52,7 +52,7 @@ protected:
 
     void upsertFile(const std::string & path, const std::string & data) override;
 
-    std::string getFile(const std::string & path) override;
+    std::shared_ptr<std::string> getFile(const std::string & path) override;
 
 };