| // Copyright (c) 2016 Uber Technologies, Inc. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package zapcore |
| |
| // Core is a minimal, fast logger interface. It's designed for library authors |
| // to wrap in a more user-friendly API. |
| type Core interface { |
| LevelEnabler |
| |
| // With adds structured context to the Core. |
| With([]Field) Core |
| // Check determines whether the supplied Entry should be logged (using the |
| // embedded LevelEnabler and possibly some extra logic). If the entry |
| // should be logged, the Core adds itself to the CheckedEntry and returns |
| // the result. |
| // |
| // Callers must use Check before calling Write. |
| Check(Entry, *CheckedEntry) *CheckedEntry |
| // Write serializes the Entry and any Fields supplied at the log site and |
| // writes them to their destination. |
| // |
| // If called, Write should always log the Entry and Fields; it should not |
| // replicate the logic of Check. |
| Write(Entry, []Field) error |
| // Sync flushes buffered logs (if any). |
| Sync() error |
| } |
| |
| type nopCore struct{} |
| |
| // NewNopCore returns a no-op Core. |
| func NewNopCore() Core { return nopCore{} } |
| func (nopCore) Enabled(Level) bool { return false } |
| func (n nopCore) With([]Field) Core { return n } |
| func (nopCore) Check(_ Entry, ce *CheckedEntry) *CheckedEntry { return ce } |
| func (nopCore) Write(Entry, []Field) error { return nil } |
| func (nopCore) Sync() error { return nil } |
| |
| // NewCore creates a Core that writes logs to a WriteSyncer. |
| func NewCore(enc Encoder, ws WriteSyncer, enab LevelEnabler) Core { |
| return &ioCore{ |
| LevelEnabler: enab, |
| enc: enc, |
| out: ws, |
| } |
| } |
| |
| type ioCore struct { |
| LevelEnabler |
| enc Encoder |
| out WriteSyncer |
| } |
| |
| func (c *ioCore) With(fields []Field) Core { |
| clone := c.clone() |
| addFields(clone.enc, fields) |
| return clone |
| } |
| |
| func (c *ioCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry { |
| if c.Enabled(ent.Level) { |
| return ce.AddCore(ent, c) |
| } |
| return ce |
| } |
| |
| func (c *ioCore) Write(ent Entry, fields []Field) error { |
| buf, err := c.enc.EncodeEntry(ent, fields) |
| if err != nil { |
| return err |
| } |
| _, err = c.out.Write(buf.Bytes()) |
| buf.Free() |
| if err != nil { |
| return err |
| } |
| if ent.Level > ErrorLevel { |
| // Since we may be crashing the program, sync the output. Ignore Sync |
| // errors, pending a clean solution to issue #370. |
| c.Sync() |
| } |
| return nil |
| } |
| |
| func (c *ioCore) Sync() error { |
| return c.out.Sync() |
| } |
| |
| func (c *ioCore) clone() *ioCore { |
| return &ioCore{ |
| LevelEnabler: c.LevelEnabler, |
| enc: c.enc.Clone(), |
| out: c.out, |
| } |
| } |