|
| 1 | +// The MIT License |
| 2 | +// |
| 3 | +// Copyright (c) 2020 Temporal Technologies Inc. All rights reserved. |
| 4 | +// |
| 5 | +// Copyright (c) 2020 Uber Technologies, Inc. |
| 6 | +// |
| 7 | +// Permission is hereby granted, free of charge, to any person obtaining a copy |
| 8 | +// of this software and associated documentation files (the "Software"), to deal |
| 9 | +// in the Software without restriction, including without limitation the rights |
| 10 | +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 11 | +// copies of the Software, and to permit persons to whom the Software is |
| 12 | +// furnished to do so, subject to the following conditions: |
| 13 | +// |
| 14 | +// The above copyright notice and this permission notice shall be included in |
| 15 | +// all copies or substantial portions of the Software. |
| 16 | +// |
| 17 | +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 18 | +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 19 | +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 20 | +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 21 | +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 22 | +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 23 | +// THE SOFTWARE. |
| 24 | + |
| 25 | +package tqname |
| 26 | + |
| 27 | +import ( |
| 28 | + "errors" |
| 29 | + "fmt" |
| 30 | + "strconv" |
| 31 | + "strings" |
| 32 | +) |
| 33 | + |
| 34 | +const ( |
| 35 | + // mangledTaskQueuePrefix is the prefix for all mangled task queue names. |
| 36 | + mangledTaskQueuePrefix = "/_sys/" |
| 37 | + |
| 38 | + suffixDelimiter = "/" |
| 39 | + versionSetDelimiter = ":" |
| 40 | +) |
| 41 | + |
| 42 | +type ( |
| 43 | + // Name encapsulates all the name mangling we do for task queues. |
| 44 | + // |
| 45 | + // Users work with "high-level task queues" and can give them arbitrary names (except for |
| 46 | + // our prefix). |
| 47 | + // |
| 48 | + // Each high-level task queue corresponds to one or more "low-level task queues", each of |
| 49 | + // which has a distinct task queue manager in memory in matching service, as well as a |
| 50 | + // distinct identity in persistence. |
| 51 | + // |
| 52 | + // There are two pieces of identifying information for low-level task queues: a partition |
| 53 | + // index, and a version set identifier. All low-level task queues have a partition index, |
| 54 | + // which may be 0. Partition 0 is called the "root". The version set identifier is |
| 55 | + // optional: task queues with it are called "versioned" and task queues without it are |
| 56 | + // called "unversioned". |
| 57 | + // |
| 58 | + // All versioned low-level task queues use mangled names. All unversioned low-level task |
| 59 | + // queues with non-zero partition also use mangled names. |
| 60 | + // |
| 61 | + // Mangled names look like this: |
| 62 | + // |
| 63 | + // /_sys/<base name>/[<version set id>:]<partition id> |
| 64 | + // |
| 65 | + // The partition id is required, and the version set id is optional. If present, it is |
| 66 | + // separated from the partition id by a colon. This scheme lets users use anything they |
| 67 | + // like for a base name, except for strings starting with "/_sys/", without ambiguity. |
| 68 | + // |
| 69 | + // For backward compatibility, unversioned low-level task queues with partition 0 do not |
| 70 | + // use mangled names, they use the bare base name. |
| 71 | + Name struct { |
| 72 | + baseName string // base name of the task queue as specified by user |
| 73 | + partition int // partition of task queue |
| 74 | + versionSet string // version set id |
| 75 | + } |
| 76 | +) |
| 77 | + |
| 78 | +var ( |
| 79 | + ErrNoParent = errors.New("root task queue partition has no parent") |
| 80 | + ErrInvalidDegree = errors.New("invalid task queue partition branching degree") |
| 81 | +) |
| 82 | + |
| 83 | +// Parse takes a mangled low-level task queue name and returns a Name. Returns an error if the |
| 84 | +// given name is not a valid mangled name. |
| 85 | +func Parse(name string) (Name, error) { |
| 86 | + baseName := name |
| 87 | + partition := 0 |
| 88 | + versionSet := "" |
| 89 | + |
| 90 | + if strings.HasPrefix(name, mangledTaskQueuePrefix) { |
| 91 | + suffixOff := strings.LastIndex(name, suffixDelimiter) |
| 92 | + if suffixOff <= len(mangledTaskQueuePrefix) { |
| 93 | + return Name{}, fmt.Errorf("invalid task queue name %q", name) |
| 94 | + } |
| 95 | + baseName = name[len(mangledTaskQueuePrefix):suffixOff] |
| 96 | + |
| 97 | + suffix := name[suffixOff+1:] |
| 98 | + if partitionOff := strings.LastIndex(suffix, versionSetDelimiter); partitionOff == 0 { |
| 99 | + return Name{}, fmt.Errorf("invalid task queue name %q", name) |
| 100 | + } else if partitionOff > 0 { |
| 101 | + // pull out version set |
| 102 | + versionSet, suffix = suffix[:partitionOff], suffix[partitionOff+1:] |
| 103 | + } |
| 104 | + |
| 105 | + var err error |
| 106 | + partition, err = strconv.Atoi(suffix) |
| 107 | + if err != nil || partition < 0 || partition == 0 && len(versionSet) == 0 { |
| 108 | + return Name{}, fmt.Errorf("invalid task queue name %q", name) |
| 109 | + } |
| 110 | + } |
| 111 | + |
| 112 | + return Name{ |
| 113 | + baseName: baseName, |
| 114 | + partition: partition, |
| 115 | + versionSet: versionSet, |
| 116 | + }, nil |
| 117 | +} |
| 118 | + |
| 119 | +// FromBaseName takes a base name and returns a Name. Returns an error if name looks like a |
| 120 | +// mangled name. |
| 121 | +func FromBaseName(name string) (Name, error) { |
| 122 | + if strings.HasPrefix(name, mangledTaskQueuePrefix) { |
| 123 | + return Name{}, fmt.Errorf("base name %q must not have prefix %q", name, mangledTaskQueuePrefix) |
| 124 | + } |
| 125 | + return Name{baseName: name}, nil |
| 126 | +} |
| 127 | + |
| 128 | +// IsRoot returns true if this task queue is a root partition. |
| 129 | +func (tn Name) IsRoot() bool { |
| 130 | + return tn.partition == 0 |
| 131 | +} |
| 132 | + |
| 133 | +// WithPartition returns a new Name with the same base and version set but a different partition. |
| 134 | +func (tn Name) WithPartition(partition int) Name { |
| 135 | + nn := tn |
| 136 | + nn.partition = partition |
| 137 | + return nn |
| 138 | +} |
| 139 | + |
| 140 | +// Root is shorthand for WithPartition(0). |
| 141 | +func (tn Name) Root() Name { |
| 142 | + return tn.WithPartition(0) |
| 143 | +} |
| 144 | + |
| 145 | +// WithVersionSet returns a new Name with the same base and partition but a different version set. |
| 146 | +func (tn Name) WithVersionSet(versionSet string) Name { |
| 147 | + nn := tn |
| 148 | + nn.versionSet = versionSet |
| 149 | + return nn |
| 150 | +} |
| 151 | + |
| 152 | +// BaseNameString returns the base name for a task queue. This should be used when looking up |
| 153 | +// settings in dynamic config, and pretty much nowhere else. To get the name of the root |
| 154 | +// partition, use tn.Root().FullName(). |
| 155 | +func (tn Name) BaseNameString() string { |
| 156 | + return tn.baseName |
| 157 | +} |
| 158 | + |
| 159 | +// Partition returns the partition number for a task queue. |
| 160 | +func (tn Name) Partition() int { |
| 161 | + return tn.partition |
| 162 | +} |
| 163 | + |
| 164 | +// VersionSet returns the version set for a task queue. |
| 165 | +func (tn Name) VersionSet() string { |
| 166 | + return tn.versionSet |
| 167 | +} |
| 168 | + |
| 169 | +// Parent returns a Name for the parent partition, using the given branching degree. |
| 170 | +func (tn Name) Parent(degree int) (Name, error) { |
| 171 | + if tn.IsRoot() { |
| 172 | + return Name{}, ErrNoParent |
| 173 | + } else if degree < 1 { |
| 174 | + return Name{}, ErrInvalidDegree |
| 175 | + } |
| 176 | + parent := (tn.partition+degree-1)/degree - 1 |
| 177 | + return tn.WithPartition(parent), nil |
| 178 | +} |
| 179 | + |
| 180 | +// FullName returns the mangled name of the task queue, to be used in RPCs and persistence. |
| 181 | +func (tn Name) FullName() string { |
| 182 | + if len(tn.versionSet) == 0 { |
| 183 | + if tn.partition == 0 { |
| 184 | + return tn.baseName |
| 185 | + } |
| 186 | + return fmt.Sprintf("%s%s%s%d", mangledTaskQueuePrefix, tn.baseName, suffixDelimiter, tn.partition) |
| 187 | + } |
| 188 | + // versioned always use prefix |
| 189 | + return fmt.Sprintf("%s%s%s%s%s%d", mangledTaskQueuePrefix, tn.baseName, suffixDelimiter, tn.versionSet, versionSetDelimiter, tn.partition) |
| 190 | +} |
0 commit comments