github.com/inspektor-gadget/inspektor-gadget@v0.28.1/pkg/gadget-collection/gadgets/profile/block-io/gadget.go (about)

     1  // Copyright 2019-2021 The Inspektor Gadget authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package biolatency
    16  
    17  import (
    18  	"fmt"
    19  
    20  	gadgetv1alpha1 "github.com/inspektor-gadget/inspektor-gadget/pkg/apis/gadget/v1alpha1"
    21  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadget-collection/gadgets"
    22  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadget-collection/gadgets/profile"
    23  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/profile/block-io/tracer"
    24  )
    25  
    26  type Trace struct {
    27  	helpers gadgets.GadgetHelpers
    28  
    29  	started bool
    30  	tracer  profile.Tracer
    31  }
    32  
    33  type TraceFactory struct {
    34  	gadgets.BaseFactory
    35  }
    36  
    37  func NewFactory() gadgets.TraceFactory {
    38  	return &TraceFactory{
    39  		BaseFactory: gadgets.BaseFactory{DeleteTrace: deleteTrace},
    40  	}
    41  }
    42  
    43  func (f *TraceFactory) Description() string {
    44  	return `The biolatency gadget traces block device I/O (disk I/O), and records the
    45  distribution of I/O latency (time), giving this as a histogram when it is
    46  stopped.`
    47  }
    48  
    49  func (f *TraceFactory) OutputModesSupported() map[gadgetv1alpha1.TraceOutputMode]struct{} {
    50  	return map[gadgetv1alpha1.TraceOutputMode]struct{}{
    51  		gadgetv1alpha1.TraceOutputModeStatus: {},
    52  	}
    53  }
    54  
    55  func deleteTrace(name string, t interface{}) {
    56  	trace := t.(*Trace)
    57  	if trace.tracer != nil && trace.started {
    58  		trace.tracer.Stop()
    59  	}
    60  }
    61  
    62  func (f *TraceFactory) Operations() map[gadgetv1alpha1.Operation]gadgets.TraceOperation {
    63  	n := func() interface{} {
    64  		return &Trace{}
    65  	}
    66  
    67  	return map[gadgetv1alpha1.Operation]gadgets.TraceOperation{
    68  		gadgetv1alpha1.OperationStart: {
    69  			Doc: "Start biolatency",
    70  			Operation: func(name string, trace *gadgetv1alpha1.Trace) {
    71  				f.LookupOrCreate(name, n).(*Trace).Start(trace)
    72  			},
    73  		},
    74  		gadgetv1alpha1.OperationStop: {
    75  			Doc: "Stop biolatency and store results",
    76  			Operation: func(name string, trace *gadgetv1alpha1.Trace) {
    77  				f.LookupOrCreate(name, n).(*Trace).Stop(trace)
    78  			},
    79  		},
    80  	}
    81  }
    82  
    83  func (t *Trace) Start(trace *gadgetv1alpha1.Trace) {
    84  	if trace.Spec.Filter != nil {
    85  		trace.Status.OperationError = "Invalid filter: Filtering is not supported"
    86  		return
    87  	}
    88  
    89  	if t.started {
    90  		trace.Status.State = gadgetv1alpha1.TraceStateStarted
    91  		return
    92  	}
    93  
    94  	var err error
    95  	t.tracer, err = tracer.NewTracer()
    96  	if err != nil {
    97  		trace.Status.OperationError = fmt.Sprintf("failed to create tracer: %s", err)
    98  		return
    99  	}
   100  	t.started = true
   101  
   102  	trace.Status.Output = ""
   103  	trace.Status.State = gadgetv1alpha1.TraceStateStarted
   104  }
   105  
   106  func (t *Trace) Stop(trace *gadgetv1alpha1.Trace) {
   107  	if !t.started {
   108  		trace.Status.OperationError = "Not started"
   109  		return
   110  	}
   111  
   112  	defer func() {
   113  		t.started = false
   114  		t.tracer = nil
   115  	}()
   116  
   117  	output, err := t.tracer.Stop()
   118  	if err != nil {
   119  		trace.Status.OperationError = err.Error()
   120  		return
   121  	}
   122  
   123  	trace.Status.Output = output
   124  	trace.Status.State = gadgetv1alpha1.TraceStateCompleted
   125  }