| // Copyright 2017 The LUCI 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. |
| |
| package venv |
| |
| import ( |
| "context" |
| "io" |
| "os" |
| "strings" |
| |
| "go.chromium.org/luci/common/data/rand/mathrand" |
| "go.chromium.org/luci/common/errors" |
| "go.chromium.org/luci/common/logging" |
| ) |
| |
| // forEachReadDirSize is the number of entries to read in a directory at a time |
| // when iterating over VirtualEnv. |
| const forEachReadDirSize = 128 |
| |
| // Iterator iterates over the contents of a "vpython" configuration directory, |
| // returning all associated VirtualEnv instances. |
| type Iterator struct { |
| // Only return VirtualEnv entries with completion flags. |
| OnlyComplete bool |
| |
| // Shuffle VirtualEnv results before returning them. |
| Shuffle bool |
| } |
| |
| // ForEach iterates over all VirtualEnv installations for the supplied "cfg". |
| // |
| // "cb" will be invoked for each VirtualEnv, regardless of its completion |
| // status. The callback may perform additional operations on the VirtualEnv to |
| // determine its actual status. If the callback returns an error, iteration will |
| // stop and the error will be forwarded. |
| // |
| // If the supplied Context is cancelled, iteration will stop prematurely and |
| // return the Context's error. |
| func (it *Iterator) ForEach(c context.Context, cfg *Config, cb func(context.Context, *Env) error) error { |
| return iterDir(c, cfg.BaseDir, func(fileInfos []os.FileInfo) error { |
| if it.Shuffle { |
| for i := range fileInfos { |
| j := mathrand.Intn(c, i+1) |
| fileInfos[i], fileInfos[j] = fileInfos[j], fileInfos[i] |
| } |
| } |
| |
| for _, fi := range fileInfos { |
| // Ignore hidden files. |
| if !fi.IsDir() || strings.HasPrefix(fi.Name(), ".") { |
| continue |
| } |
| |
| e := cfg.envForName(fi.Name(), nil) |
| if it.OnlyComplete { |
| if err := e.AssertCompleteAndLoad(); err != nil { |
| logging.WithError(err).Debugf(c, "Skipping VirtualEnv %s; not complete.", fi.Name()) |
| continue |
| } |
| } |
| |
| if err := cb(c, e); err != nil { |
| return err |
| } |
| } |
| |
| return nil |
| }) |
| } |
| |
| func iterDir(c context.Context, dirPath string, cb func([]os.FileInfo) error) error { |
| // Get a listing of all VirtualEnv within the base directory. |
| dir, err := os.Open(dirPath) |
| if err != nil { |
| return errors.Annotate(err, "failed to open base directory: %s", dirPath).Err() |
| } |
| defer dir.Close() |
| |
| for done := false; !done; { |
| // Check if we've been cancelled. |
| select { |
| case <-c.Done(): |
| return c.Err() |
| default: |
| } |
| |
| // Read the next batch of directories. |
| fileInfos, err := dir.Readdir(forEachReadDirSize) |
| switch err { |
| case nil: |
| |
| case io.EOF: |
| done = true |
| |
| default: |
| return errors.Annotate(err, "could not read directory contents: %s", dirPath).Err() |
| } |
| |
| if err := cb(fileInfos); err != nil { |
| return err |
| } |
| } |
| |
| return nil |
| } |