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| 1 | +package datastore |
| 2 | + |
| 3 | +import ( |
| 4 | + "io" |
| 5 | + "log" |
| 6 | + |
| 7 | + dsq "github.com/ipfs/fs-repo-migrations/ipfs-4-to-5/go-datastore/query" |
| 8 | +) |
| 9 | + |
| 10 | +// Here are some basic datastore implementations. |
| 11 | + |
| 12 | +type keyMap map[Key]interface{} |
| 13 | + |
| 14 | +// MapDatastore uses a standard Go map for internal storage. |
| 15 | +type MapDatastore struct { |
| 16 | + values keyMap |
| 17 | +} |
| 18 | + |
| 19 | +// NewMapDatastore constructs a MapDatastore |
| 20 | +func NewMapDatastore() (d *MapDatastore) { |
| 21 | + return &MapDatastore{ |
| 22 | + values: keyMap{}, |
| 23 | + } |
| 24 | +} |
| 25 | + |
| 26 | +// Put implements Datastore.Put |
| 27 | +func (d *MapDatastore) Put(key Key, value interface{}) (err error) { |
| 28 | + d.values[key] = value |
| 29 | + return nil |
| 30 | +} |
| 31 | + |
| 32 | +// Get implements Datastore.Get |
| 33 | +func (d *MapDatastore) Get(key Key) (value interface{}, err error) { |
| 34 | + val, found := d.values[key] |
| 35 | + if !found { |
| 36 | + return nil, ErrNotFound |
| 37 | + } |
| 38 | + return val, nil |
| 39 | +} |
| 40 | + |
| 41 | +// Has implements Datastore.Has |
| 42 | +func (d *MapDatastore) Has(key Key) (exists bool, err error) { |
| 43 | + _, found := d.values[key] |
| 44 | + return found, nil |
| 45 | +} |
| 46 | + |
| 47 | +// Delete implements Datastore.Delete |
| 48 | +func (d *MapDatastore) Delete(key Key) (err error) { |
| 49 | + if _, found := d.values[key]; !found { |
| 50 | + return ErrNotFound |
| 51 | + } |
| 52 | + delete(d.values, key) |
| 53 | + return nil |
| 54 | +} |
| 55 | + |
| 56 | +// Query implements Datastore.Query |
| 57 | +func (d *MapDatastore) Query(q dsq.Query) (dsq.Results, error) { |
| 58 | + re := make([]dsq.Entry, 0, len(d.values)) |
| 59 | + for k, v := range d.values { |
| 60 | + re = append(re, dsq.Entry{Key: k.String(), Value: v}) |
| 61 | + } |
| 62 | + r := dsq.ResultsWithEntries(q, re) |
| 63 | + r = dsq.NaiveQueryApply(q, r) |
| 64 | + return r, nil |
| 65 | +} |
| 66 | + |
| 67 | +func (d *MapDatastore) Batch() (Batch, error) { |
| 68 | + return NewBasicBatch(d), nil |
| 69 | +} |
| 70 | + |
| 71 | +func (d *MapDatastore) Close() error { |
| 72 | + return nil |
| 73 | +} |
| 74 | + |
| 75 | +// NullDatastore stores nothing, but conforms to the API. |
| 76 | +// Useful to test with. |
| 77 | +type NullDatastore struct { |
| 78 | +} |
| 79 | + |
| 80 | +// NewNullDatastore constructs a null datastoe |
| 81 | +func NewNullDatastore() *NullDatastore { |
| 82 | + return &NullDatastore{} |
| 83 | +} |
| 84 | + |
| 85 | +// Put implements Datastore.Put |
| 86 | +func (d *NullDatastore) Put(key Key, value interface{}) (err error) { |
| 87 | + return nil |
| 88 | +} |
| 89 | + |
| 90 | +// Get implements Datastore.Get |
| 91 | +func (d *NullDatastore) Get(key Key) (value interface{}, err error) { |
| 92 | + return nil, nil |
| 93 | +} |
| 94 | + |
| 95 | +// Has implements Datastore.Has |
| 96 | +func (d *NullDatastore) Has(key Key) (exists bool, err error) { |
| 97 | + return false, nil |
| 98 | +} |
| 99 | + |
| 100 | +// Delete implements Datastore.Delete |
| 101 | +func (d *NullDatastore) Delete(key Key) (err error) { |
| 102 | + return nil |
| 103 | +} |
| 104 | + |
| 105 | +// Query implements Datastore.Query |
| 106 | +func (d *NullDatastore) Query(q dsq.Query) (dsq.Results, error) { |
| 107 | + return dsq.ResultsWithEntries(q, nil), nil |
| 108 | +} |
| 109 | + |
| 110 | +func (d *NullDatastore) Batch() (Batch, error) { |
| 111 | + return NewBasicBatch(d), nil |
| 112 | +} |
| 113 | + |
| 114 | +func (d *NullDatastore) Close() error { |
| 115 | + return nil |
| 116 | +} |
| 117 | + |
| 118 | +// LogDatastore logs all accesses through the datastore. |
| 119 | +type LogDatastore struct { |
| 120 | + Name string |
| 121 | + child Datastore |
| 122 | +} |
| 123 | + |
| 124 | +// Shim is a datastore which has a child. |
| 125 | +type Shim interface { |
| 126 | + Datastore |
| 127 | + |
| 128 | + Children() []Datastore |
| 129 | +} |
| 130 | + |
| 131 | +// NewLogDatastore constructs a log datastore. |
| 132 | +func NewLogDatastore(ds Datastore, name string) *LogDatastore { |
| 133 | + if len(name) < 1 { |
| 134 | + name = "LogDatastore" |
| 135 | + } |
| 136 | + return &LogDatastore{Name: name, child: ds} |
| 137 | +} |
| 138 | + |
| 139 | +// Children implements Shim |
| 140 | +func (d *LogDatastore) Children() []Datastore { |
| 141 | + return []Datastore{d.child} |
| 142 | +} |
| 143 | + |
| 144 | +// Put implements Datastore.Put |
| 145 | +func (d *LogDatastore) Put(key Key, value interface{}) (err error) { |
| 146 | + log.Printf("%s: Put %s\n", d.Name, key) |
| 147 | + // log.Printf("%s: Put %s ```%s```", d.Name, key, value) |
| 148 | + return d.child.Put(key, value) |
| 149 | +} |
| 150 | + |
| 151 | +// Get implements Datastore.Get |
| 152 | +func (d *LogDatastore) Get(key Key) (value interface{}, err error) { |
| 153 | + log.Printf("%s: Get %s\n", d.Name, key) |
| 154 | + return d.child.Get(key) |
| 155 | +} |
| 156 | + |
| 157 | +// Has implements Datastore.Has |
| 158 | +func (d *LogDatastore) Has(key Key) (exists bool, err error) { |
| 159 | + log.Printf("%s: Has %s\n", d.Name, key) |
| 160 | + return d.child.Has(key) |
| 161 | +} |
| 162 | + |
| 163 | +// Delete implements Datastore.Delete |
| 164 | +func (d *LogDatastore) Delete(key Key) (err error) { |
| 165 | + log.Printf("%s: Delete %s\n", d.Name, key) |
| 166 | + return d.child.Delete(key) |
| 167 | +} |
| 168 | + |
| 169 | +// Query implements Datastore.Query |
| 170 | +func (d *LogDatastore) Query(q dsq.Query) (dsq.Results, error) { |
| 171 | + log.Printf("%s: Query\n", d.Name) |
| 172 | + return d.child.Query(q) |
| 173 | +} |
| 174 | + |
| 175 | +func (d *LogDatastore) Batch() (Batch, error) { |
| 176 | + log.Printf("%s: Batch\n", d.Name) |
| 177 | + if bds, ok := d.child.(Batching); ok { |
| 178 | + return bds.Batch() |
| 179 | + } |
| 180 | + return nil, ErrBatchUnsupported |
| 181 | +} |
| 182 | + |
| 183 | +func (d *LogDatastore) Close() error { |
| 184 | + log.Printf("%s: Close\n", d.Name) |
| 185 | + if cds, ok := d.child.(io.Closer); ok { |
| 186 | + return cds.Close() |
| 187 | + } |
| 188 | + return nil |
| 189 | +} |
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