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fuchsia / third_party / github.com / go-yaml / yaml / refs/tags/v2.2.8
commit53403b58ad1b561927d19068c655246f2db79d48[log] [tgz]
authorCJ Cullen <cjcullen@google.com>Tue Jan 21 09:19:40 2020 -0800
committerGustavo Niemeyer <gustavo@niemeyer.net>Tue Jan 21 17:19:40 2020 +0000
treee7d2c759f02ee6296e7a48b9b9b80a027e5a0804
parent1f64d6156d11335c3f22d9330b0ad14fc1e789ce [diff]
Optimize cases with long potential simple_keys (#555)

This change introduces an index to lookup token numbers referenced by simple_keys in O(1),
thus significantly reducing the performance impact of certain abusively constructed snippets.

When we build up the simple_keys stack, we count on the (formerly named) staleness check to
catch errors where a simple key is required but would be > 1024 chars or span lines. The previous
simplification that searches the stack from the top can go 1024 keys deep before finding a "stale"
key and stopping. I added a test that shows that this consumes ~3s per 1MB of document size.
3 files changed
tree: e7d2c759f02ee6296e7a48b9b9b80a027e5a0804
  1. .travis.yml
  2. apic.go
  3. decode.go
  4. decode_test.go
  5. emitterc.go
  6. encode.go
  7. encode_test.go
  8. example_embedded_test.go
  9. go.mod
  10. LICENSE
  11. LICENSE.libyaml
  12. limit_test.go
  13. NOTICE
  14. parserc.go
  15. readerc.go
  16. README.md
  17. resolve.go
  18. scannerc.go
  19. sorter.go
  20. suite_test.go
  21. writerc.go
  22. yaml.go
  23. yamlh.go
  24. yamlprivateh.go
README.md

YAML support for the Go language

Introduction

The yaml package enables Go programs to comfortably encode and decode YAML values. It was developed within Canonical as part of the juju project, and is based on a pure Go port of the well-known libyaml C library to parse and generate YAML data quickly and reliably.

Compatibility

The yaml package supports most of YAML 1.1 and 1.2, including support for anchors, tags, map merging, etc. Multi-document unmarshalling is not yet implemented, and base-60 floats from YAML 1.1 are purposefully not supported since they're a poor design and are gone in YAML 1.2.

Installation and usage

The import path for the package is gopkg.in/yaml.v2.

To install it, run:

go get gopkg.in/yaml.v2

API documentation

If opened in a browser, the import path itself leads to the API documentation:

API stability

The package API for yaml v2 will remain stable as described in gopkg.in.

License

The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.

Example

package main

import (
        "fmt"
        "log"

        "gopkg.in/yaml.v2"
)

var data = `
a: Easy!
b:
  c: 2
  d: [3, 4]
`

// Note: struct fields must be public in order for unmarshal to
// correctly populate the data.
type T struct {
        A string
        B struct {
                RenamedC int   `yaml:"c"`
                D        []int `yaml:",flow"`
        }
}

func main() {
        t := T{}
    
        err := yaml.Unmarshal([]byte(data), &t)
        if err != nil {
                log.Fatalf("error: %v", err)
        }
        fmt.Printf("--- t:\n%v\n\n", t)
    
        d, err := yaml.Marshal(&t)
        if err != nil {
                log.Fatalf("error: %v", err)
        }
        fmt.Printf("--- t dump:\n%s\n\n", string(d))
    
        m := make(map[interface{}]interface{})
    
        err = yaml.Unmarshal([]byte(data), &m)
        if err != nil {
                log.Fatalf("error: %v", err)
        }
        fmt.Printf("--- m:\n%v\n\n", m)
    
        d, err = yaml.Marshal(&m)
        if err != nil {
                log.Fatalf("error: %v", err)
        }
        fmt.Printf("--- m dump:\n%s\n\n", string(d))
}

This example will generate the following output:

--- t:
{Easy! {2 [3 4]}}

--- t dump:
a: Easy!
b:
  c: 2
  d: [3, 4]


--- m:
map[a:Easy! b:map[c:2 d:[3 4]]]

--- m dump:
a: Easy!
b:
  c: 2
  d:
  - 3
  - 4