commit | 53403b58ad1b561927d19068c655246f2db79d48 | [log] [tgz] |
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author | CJ Cullen <cjcullen@google.com> | Tue Jan 21 09:19:40 2020 -0800 |
committer | Gustavo Niemeyer <gustavo@niemeyer.net> | Tue Jan 21 17:19:40 2020 +0000 |
tree | e7d2c759f02ee6296e7a48b9b9b80a027e5a0804 | |
parent | 1f64d6156d11335c3f22d9330b0ad14fc1e789ce [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.
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.
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.
The import path for the package is gopkg.in/yaml.v2.
To install it, run:
go get gopkg.in/yaml.v2
If opened in a browser, the import path itself leads to the API documentation:
The package API for yaml v2 will remain stable as described in gopkg.in.
The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.
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