S3BinaryCacheStore::isValidPath(): Do a GET instead of HEAD

Dependencies

• [2] XLYHZUHT Cache .narinfo lookups
• [3] W2AOTSS6 Rename class
• [4] 32HHP5CW hydra-queue-runner: Support generating a signed binary cache
• [5] SOB276BA Keep some statistics for the binary cache stores
• [6] 73YR46NJ hydra-queue-runner: Write directly to a binary cache
• [7] GTUZLZRH Add an S3-backed binary cache store
• [8] EOO4EFWD Use a single BinaryCacheStore for all threads
• [9] N2NKSKHS Refactor local binary cache code into a subclass

Change contents

• edit in src/hydra-queue-runner/binary-cache-store.cc at line 105
  [2.218]→[2.218:219](∅→∅),[2.219]→[3.519:544](∅→∅),[3.4304]→[3.519:544](∅→∅)
  −

  − stats.narInfoRead++;
• edit in src/hydra-queue-runner/binary-cache-store.cc at line 109
  [2.333]

  [3.5476]
  +

  + stats.narInfoRead++;
• edit in src/hydra-queue-runner/binary-cache-store.hh at line 76
  [3.9630]

  [3.9719]
  +

  + protected:
• edit in src/hydra-queue-runner/s3-binary-cache-store.cc at line 2
  [3.1334]

  [3.1334]
  +

  + #include "nar-info.hh"
• edit in src/hydra-queue-runner/s3-binary-cache-store.cc at line 14
  [3.1657]

  [3.1657]
  +

  + struct S3Error : public Error

  + {

  + Aws::S3::S3Errors err;

  + S3Error(Aws::S3::S3Errors err, const FormatOrString & fs)

  + : Error(fs), err(err) { };

  + };
• replacement in src/hydra-queue-runner/s3-binary-cache-store.cc at line 28
  [3.1888]→[3.1888:1969](∅→∅)
  − throw Error(format("AWS error: %1%") % outcome.GetError().GetMessage());
  [3.1888]

  [3.1969]
  + throw S3Error(

  + outcome.GetError().GetErrorType(),

  + format("AWS error: %1%") % outcome.GetError().GetMessage());
• edit in src/hydra-queue-runner/s3-binary-cache-store.cc at line 79
  [3.4987]

  [3.3480]
  + }

  +

  + /* This is a specialisation of isValidPath() that optimistically

  + fetches the .narinfo file, rather than first checking for its

  + existence via a HEAD request. Since .narinfos are small, doing a

  + GET is unlikely to be slower than HEAD. */

  + 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;

  + }
• edit in src/hydra-queue-runner/s3-binary-cache-store.hh at line 41
  [3.5862]

  [3.5862]
  +

  + bool isValidPath(const Path & storePath) override;