go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/server/quota/module.go (about)

     1  // Copyright 2022 The LUCI 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 quota
    16  
    17  import (
    18  	"context"
    19  	"flag"
    20  
    21  	"github.com/gomodule/redigo/redis"
    22  
    23  	"go.chromium.org/luci/common/errors"
    24  	"go.chromium.org/luci/common/logging"
    25  
    26  	"go.chromium.org/luci/server/module"
    27  	"go.chromium.org/luci/server/quota/quotapb"
    28  	"go.chromium.org/luci/server/redisconn"
    29  )
    30  
    31  // ModuleName is the globally-unique name for this module.
    32  // Useful for registering this module as a dependency of other modules.
    33  var ModuleName = module.RegisterName("go.chromium.org/luci/server/quota")
    34  
    35  // Ensure quotaModule implements server.Module at compile-time.
    36  var _ module.Module = &quotaModule{}
    37  
    38  // quotaModule implements module.Module.
    39  type quotaModule struct {
    40  	opts *ModuleOptions
    41  }
    42  
    43  var stateKey = "holds a *quotaModuleState"
    44  
    45  type quotaModuleState struct {
    46  	pool *redis.Pool
    47  }
    48  
    49  // Dependencies returns required and optional dependencies for this module.
    50  // Implements module.Module.
    51  func (*quotaModule) Dependencies() []module.Dependency {
    52  	return []module.Dependency{
    53  		module.RequiredDependency(redisconn.ModuleName),
    54  	}
    55  }
    56  
    57  func withRedisConn(ctx context.Context, cb func(redis.Conn) error) (err error) {
    58  	conn, err := redisconn.Get(ctx)
    59  	if err != nil {
    60  		err = errors.Annotate(err, "quota: unable to get redis connection").Err()
    61  		return
    62  	}
    63  	defer func() {
    64  		if err := conn.Close(); err != nil {
    65  			logging.Errorf(ctx, "quota: unable to close redis connection: %s", err)
    66  		}
    67  	}()
    68  	return cb(conn)
    69  }
    70  
    71  // Initialize initializes this module by setting ModuleOptions in the context
    72  // and optionally registering the admin service.
    73  //
    74  // Implements module.Module.
    75  func (m *quotaModule) Initialize(ctx context.Context, host module.Host, opts module.HostOptions) (context.Context, error) {
    76  	quotapb.RegisterAdminServer(host, &quotaAdmin{})
    77  	return ctx, nil
    78  }
    79  
    80  // Name returns the module.Name for this module.
    81  // Implements module.Module.
    82  func (*quotaModule) Name() module.Name {
    83  	return ModuleName
    84  }
    85  
    86  // ModuleOptions is a set of configuration options for the quota module.
    87  type ModuleOptions struct {
    88  	// TODO(iannucci): add option to select alternate database?
    89  }
    90  
    91  // Register adds command line flags for these module options to the given
    92  // *flag.FlagSet. Mutates module options by initializing defaults.
    93  func (o *ModuleOptions) Register(f *flag.FlagSet) {
    94  }
    95  
    96  // NewModule returns a module.Module for the quota library initialized from the
    97  // given *ModuleOptions.
    98  func NewModule(opts *ModuleOptions) module.Module {
    99  	return &quotaModule{}
   100  }
   101  
   102  // NewModuleFromFlags returns a module.Module for the quota library which can be
   103  // initialized from command line flags.
   104  func NewModuleFromFlags() module.Module {
   105  	return NewModule(nil)
   106  }