github.com/Laisky/zap@v1.27.0/zapcore/hook.go (about)

     1  // Copyright (c) 2016 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package zapcore
    22  
    23  import "go.uber.org/multierr"
    24  
    25  type hooked struct {
    26  	Core
    27  	funcs []func(Entry) error
    28  }
    29  
    30  var (
    31  	_ Core           = (*hooked)(nil)
    32  	_ leveledEnabler = (*hooked)(nil)
    33  )
    34  
    35  type hookedWithFields struct {
    36  	Core
    37  	funcs []func(Entry, []Field) error
    38  }
    39  
    40  // RegisterHooks wraps a Core and runs a collection of user-defined callback
    41  // hooks each time a message is logged. Execution of the callbacks is blocking.
    42  //
    43  // This offers users an easy way to register simple callbacks (e.g., metrics
    44  // collection) without implementing the full Core interface.
    45  func RegisterHooks(core Core, hooks ...func(Entry) error) Core {
    46  	funcs := append([]func(Entry) error{}, hooks...)
    47  	return &hooked{
    48  		Core:  core,
    49  		funcs: funcs,
    50  	}
    51  }
    52  
    53  func (h *hooked) Level() Level {
    54  	return LevelOf(h.Core)
    55  }
    56  
    57  // RegisterHooksWithFields like RegisterHooks but and invoke hooks with arbitary fileds
    58  func RegisterHooksWithFields(core Core, hooks ...func(Entry, []Field) error) Core {
    59  	return &hookedWithFields{
    60  		Core:  core,
    61  		funcs: hooks[:len(hooks):len(hooks)],
    62  	}
    63  }
    64  
    65  func (h *hooked) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
    66  	// Let the wrapped Core decide whether to log this message or not. This
    67  	// also gives the downstream a chance to register itself directly with the
    68  	// CheckedEntry.
    69  	if downstream := h.Core.Check(ent, ce); downstream != nil {
    70  		return downstream.AddCore(ent, h)
    71  	}
    72  	return ce
    73  }
    74  
    75  func (h *hooked) With(fields []Field) Core {
    76  	return &hooked{
    77  		Core:  h.Core.With(fields),
    78  		funcs: h.funcs,
    79  	}
    80  }
    81  
    82  func (h *hooked) Write(ent Entry, _ []Field) error {
    83  	// Since our downstream had a chance to register itself directly with the
    84  	// CheckedMessage, we don't need to call it here.
    85  	var err error
    86  	for i := range h.funcs {
    87  		err = multierr.Append(err, h.funcs[i](ent))
    88  	}
    89  	return err
    90  }
    91  
    92  func (h *hookedWithFields) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
    93  	// Let the wrapped Core decide whether to log this message or not. This
    94  	// also gives the downstream a chance to register itself directly with the
    95  	// CheckedEntry.
    96  	if downstream := h.Core.Check(ent, ce); downstream != nil {
    97  		return downstream.AddCore(ent, h)
    98  	}
    99  	return ce
   100  }
   101  
   102  func (h *hookedWithFields) With(fields []Field) Core {
   103  	return &hookedWithFields{
   104  		Core:  h.Core.With(fields),
   105  		funcs: h.funcs,
   106  	}
   107  }
   108  
   109  func (h *hookedWithFields) Write(ent Entry, fs []Field) error {
   110  	// Since our downstream had a chance to register itself directly with the
   111  	// CheckedMessage, we don't need to call it here.
   112  	var err error
   113  	for i := range h.funcs {
   114  		fs = append(fs[:len(fs):len(fs)], h.Core.Fields()...)
   115  		err = multierr.Append(err, h.funcs[i](ent, fs))
   116  	}
   117  	return err
   118  }