prometheus/storage/local/test_helpers.go
beorn7 5bea942d8e Improve various things around chunk encoding.
A number of mostly minor things:

- Rename chunk type -> chunk encoding.

- After all, do not carry around the chunk encoding to all parts of
  the system, but just have one place where the encoding for new
  chunks is set based on the flag. The new approach has caveats as
  well, but the polution of so many method signatures is worse.

- Use the default chunk encoding for new chunks of existing
  series. (Previously, only new _series_ would get chunks with the
  default encoding.)

- Use an enum for chunk encoding. (But keep the version number for the
  flag, for reasons discussed previously.)

- Add encoding() to the chunk interface (so that a chunk knows its own
  encoding - no need to have that in a different top-level function).

- Got rid of newFollowUpChunk (which would keep the existing encoding
  for all chunks of a time series). Now only use newChunk(), which
  will create a chunk encoding according to the flag.

- Simplified transcodeAndAdd.

- Reordered methods of deltaEncodedChunk and doubleDeltaEncoded chunk
  to match the order in the chunk interface.

- Only transcode if the chunk is not yet half full. If more than half
  full, add a new chunk instead.
2015-03-14 19:03:20 +01:00

64 lines
2 KiB
Go

// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// NOTE ON FILENAME: Do not rename this file helpers_test.go (which might appear
// an obvious choice). We need NewTestStorage in tests outside of the local
// package, too. On the other hand, moving NewTestStorage in its own package
// would cause circular dependencies in the tests in packages local.
package local
import (
"time"
"github.com/prometheus/prometheus/utility/test"
)
type testStorageCloser struct {
storage Storage
directory test.Closer
}
func (t *testStorageCloser) Close() {
t.storage.Stop()
t.directory.Close()
}
// NewTestStorage creates a storage instance backed by files in a temporary
// directory. The returned storage is already in serving state. Upon closing the
// returned test.Closer, the temporary directory is cleaned up.
func NewTestStorage(t test.T, encoding chunkEncoding) (Storage, test.Closer) {
*defaultChunkEncoding = int(encoding)
directory := test.NewTemporaryDirectory("test_storage", t)
o := &MemorySeriesStorageOptions{
MemoryChunks: 1000000,
PersistenceRetentionPeriod: 24 * time.Hour * 365 * 100, // Enough to never trigger purging.
PersistenceStoragePath: directory.Path(),
CheckpointInterval: time.Hour,
}
storage, err := NewMemorySeriesStorage(o)
if err != nil {
directory.Close()
t.Fatalf("Error creating storage: %s", err)
}
storage.Start()
closer := &testStorageCloser{
storage: storage,
directory: directory,
}
return storage, closer
}