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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,175 +1,176 @@ | ||
| package index | ||
|
|
||
| import ( | ||
| "bytes" | ||
| "sort" | ||
| "sync" | ||
|
|
||
| "github.com/ByteStorage/FlyDB/engine/data" | ||
| "github.com/cornelk/hashmap" | ||
| ) | ||
|
|
||
| /* | ||
| hashmap index, encapsulates the hashmap library of cornelk | ||
| */ | ||
|
|
||
| // HashMap struct | ||
| type HashMap struct { | ||
| hashmap *hashmap.Map[string, *data.LogRecordPst] | ||
| // To ensure Thread safety | ||
| // multi thread writes need to be locked | ||
| lock *sync.RWMutex | ||
| } | ||
|
|
||
| // NewHashMap create a hashmap index | ||
| func NewHashMap() *HashMap { | ||
| return &HashMap{ | ||
| hashmap: hashmap.New[string, *data.LogRecordPst](), | ||
| lock: new(sync.RWMutex), | ||
| } | ||
| } | ||
|
|
||
| // Implement the methods of the index interface | ||
| // Put stores the data location information of key into the index | ||
| func (hm *HashMap) Put(key []byte, pst *data.LogRecordPst) bool { | ||
| hm.lock.Lock() | ||
| defer hm.lock.Unlock() | ||
|
|
||
| hm.hashmap.Set(string(key), pst) | ||
| return true | ||
| } | ||
|
|
||
| // Get gains the data location of the key in the index | ||
| func (hm *HashMap) Get(key []byte) *data.LogRecordPst { | ||
| value, ok := hm.hashmap.Get(string(key)) | ||
| if !ok { | ||
| return nil | ||
| } | ||
| return value | ||
| } | ||
|
|
||
| // Delete deletes data location of one key in index | ||
| func (hm *HashMap) Delete(key []byte) bool { | ||
| hm.lock.Lock() | ||
| hm.lock.Unlock() | ||
|
|
||
| return hm.hashmap.Del(string(key)) | ||
| } | ||
|
|
||
| // Size returns the size of the data in index | ||
| func (hm *HashMap) Size() int { | ||
| return hm.hashmap.Len() | ||
| } | ||
|
|
||
| // Iterator returns a index Iterator | ||
| func (hm *HashMap) Iterator(reverse bool) Iterator { | ||
| // if the HashMap is empty, returns a default iterator | ||
| if hm.hashmap == nil { | ||
| return NewDefaultHashMapIterator(reverse) | ||
| } | ||
| hm.lock.RLock() | ||
| defer hm.lock.RUnlock() | ||
| // if the HashMap is not empty, returns a iterator | ||
| return NewHashMapIterator(hm.hashmap, reverse) | ||
| } | ||
|
|
||
| // HashMapIterator struct | ||
| type HashMapIterator struct { | ||
| currIndex int // The subscript position of the current traversal | ||
| reverse bool // Whether it is reverse traversal | ||
| values []*Item // Key + Location index information | ||
| } | ||
|
|
||
| // create a default HashMap Iterator for the empty HashMap | ||
| func NewDefaultHashMapIterator(reverse bool) *HashMapIterator { | ||
| return &HashMapIterator{ | ||
| currIndex: 0, | ||
| reverse: reverse, | ||
| values: nil, | ||
| } | ||
| } | ||
|
|
||
| // create a HashMapIterator | ||
| func NewHashMapIterator(hm *hashmap.Map[string, *data.LogRecordPst], reverse bool) *HashMapIterator { | ||
| // Use values slice to store all data in values | ||
| values := make([]*Item, hm.Len()) | ||
|
|
||
| // count the number of elements in the values slice | ||
| var count int = 0 | ||
| // store all data into an slice values | ||
| // We use range() method in the hashmap implement to do this | ||
| // define an operator method | ||
| saveFunc := func(key string, value *data.LogRecordPst) bool { | ||
| count++ | ||
| item := &Item{ | ||
| key: []byte(key), | ||
| pst: value, | ||
| } | ||
| values = append(values, item) | ||
| return true | ||
| } | ||
| // call range() method | ||
| hm.Range(saveFunc) | ||
|
|
||
| // filter out nil values | ||
| values = values[count:] | ||
|
|
||
| // if reverse needed, reverse the slice | ||
| if reverse { | ||
| for i, j := 0, len(values)-1; i < j; i, j = i+1, j-1 { | ||
| values[i], values[j] = values[j], values[i] | ||
| } | ||
| } | ||
|
|
||
| return &HashMapIterator{ | ||
| currIndex: 0, | ||
| reverse: reverse, | ||
| values: values, | ||
| } | ||
| } | ||
|
|
||
| // Rewind goes back to the begining of the Iterator,ie. the index of the first data | ||
| func (hmIt *HashMapIterator) Rewind() { | ||
| hmIt.currIndex = 0 | ||
| } | ||
|
|
||
| // Seek finds a >= or <= target key according to the incoming key, | ||
| // and starts traversing from this target key | ||
| func (hmIt *HashMapIterator) Seek(key []byte) { | ||
| if hmIt.reverse { | ||
| hmIt.currIndex = sort.Search(len(hmIt.values), func(i int) bool { | ||
| return bytes.Compare(hmIt.values[i].key, key) <= 0 | ||
| }) | ||
| } else { | ||
| hmIt.currIndex = sort.Search(len(hmIt.values), func(i int) bool { | ||
| return bytes.Compare(hmIt.values[i].key, key) >= 0 | ||
| }) | ||
| } | ||
| } | ||
|
|
||
| // Next jumps to the next key | ||
| func (hmIt *HashMapIterator) Next() { | ||
| hmIt.currIndex += 1 | ||
| } | ||
|
|
||
| // Valid refers to whether it is valid, that is, | ||
| // whether all keys have been traversed, | ||
| // used to exit the traverse ==> true->yes false-->no | ||
| func (hmIt *HashMapIterator) Valid() bool { | ||
| return hmIt.currIndex < len(hmIt.values) | ||
| } | ||
|
|
||
| // Key returns the key data at the current traversal position | ||
| func (hmIt *HashMapIterator) Key() []byte { | ||
| return hmIt.values[hmIt.currIndex].key | ||
| } | ||
|
|
||
| // Value returns the value data of the current traversal position | ||
| func (hmIt *HashMapIterator) Value() *data.LogRecordPst { | ||
| return hmIt.values[hmIt.currIndex].pst | ||
| } | ||
|
|
||
| // Close closes the iterator and releases the corresponding resources | ||
| func (hmIt *HashMapIterator) Close() { | ||
| hmIt.values = nil | ||
| } | ||
| // | ||
| //import ( | ||
| // "bytes" | ||
| // "sort" | ||
| // "sync" | ||
| // | ||
| // "github.com/ByteStorage/FlyDB/engine/data" | ||
| // "github.com/cornelk/hashmap" | ||
| //) | ||
| // | ||
| ///* | ||
| //hashmap index, encapsulates the hashmap library of cornelk | ||
| //*/ | ||
| // | ||
| //// HashMap struct | ||
| //type HashMap struct { | ||
| // hashmap *hashmap.Map[string, *data.LogRecordPst] | ||
| // // To ensure Thread safety | ||
| // // multi thread writes need to be locked | ||
| // lock *sync.RWMutex | ||
| //} | ||
| // | ||
| //// NewHashMap create a hashmap index | ||
| //func NewHashMap() *HashMap { | ||
| // return &HashMap{ | ||
| // hashmap: hashmap.New[string, *data.LogRecordPst](), | ||
| // lock: new(sync.RWMutex), | ||
| // } | ||
| //} | ||
| // | ||
| //// Implement the methods of the index interface | ||
| //// Put stores the data location information of key into the index | ||
| //func (hm *HashMap) Put(key []byte, pst *data.LogRecordPst) bool { | ||
| // hm.lock.Lock() | ||
| // defer hm.lock.Unlock() | ||
| // | ||
| // hm.hashmap.Set(string(key), pst) | ||
| // return true | ||
| //} | ||
| // | ||
| //// Get gains the data location of the key in the index | ||
| //func (hm *HashMap) Get(key []byte) *data.LogRecordPst { | ||
| // value, ok := hm.hashmap.Get(string(key)) | ||
| // if !ok { | ||
| // return nil | ||
| // } | ||
| // return value | ||
| //} | ||
| // | ||
| //// Delete deletes data location of one key in index | ||
| //func (hm *HashMap) Delete(key []byte) bool { | ||
| // hm.lock.Lock() | ||
| // hm.lock.Unlock() | ||
| // | ||
| // return hm.hashmap.Del(string(key)) | ||
| //} | ||
| // | ||
| //// Size returns the size of the data in index | ||
| //func (hm *HashMap) Size() int { | ||
| // return hm.hashmap.Len() | ||
| //} | ||
| // | ||
| //// Iterator returns a index Iterator | ||
| //func (hm *HashMap) Iterator(reverse bool) Iterator { | ||
| // // if the HashMap is empty, returns a default iterator | ||
| // if hm.hashmap == nil { | ||
| // return NewDefaultHashMapIterator(reverse) | ||
| // } | ||
| // hm.lock.RLock() | ||
| // defer hm.lock.RUnlock() | ||
| // // if the HashMap is not empty, returns a iterator | ||
| // return NewHashMapIterator(hm.hashmap, reverse) | ||
| //} | ||
| // | ||
| //// HashMapIterator struct | ||
| //type HashMapIterator struct { | ||
| // currIndex int // The subscript position of the current traversal | ||
| // reverse bool // Whether it is reverse traversal | ||
| // values []*Item // Key + Location index information | ||
| //} | ||
| // | ||
| //// create a default HashMap Iterator for the empty HashMap | ||
| //func NewDefaultHashMapIterator(reverse bool) *HashMapIterator { | ||
| // return &HashMapIterator{ | ||
| // currIndex: 0, | ||
| // reverse: reverse, | ||
| // values: nil, | ||
| // } | ||
| //} | ||
| // | ||
| //// create a HashMapIterator | ||
| //func NewHashMapIterator(hm *hashmap.Map[string, *data.LogRecordPst], reverse bool) *HashMapIterator { | ||
| // // Use values slice to store all data in values | ||
| // values := make([]*Item, hm.Len()) | ||
| // | ||
| // // count the number of elements in the values slice | ||
| // var count int = 0 | ||
| // // store all data into an slice values | ||
| // // We use range() method in the hashmap implement to do this | ||
| // // define an operator method | ||
| // saveFunc := func(key string, value *data.LogRecordPst) bool { | ||
| // count++ | ||
| // item := &Item{ | ||
| // key: []byte(key), | ||
| // pst: value, | ||
| // } | ||
| // values = append(values, item) | ||
| // return true | ||
| // } | ||
| // // call range() method | ||
| // hm.Range(saveFunc) | ||
| // | ||
| // // filter out nil values | ||
| // values = values[count:] | ||
| // | ||
| // // if reverse needed, reverse the slice | ||
| // if reverse { | ||
| // for i, j := 0, len(values)-1; i < j; i, j = i+1, j-1 { | ||
| // values[i], values[j] = values[j], values[i] | ||
| // } | ||
| // } | ||
| // | ||
| // return &HashMapIterator{ | ||
| // currIndex: 0, | ||
| // reverse: reverse, | ||
| // values: values, | ||
| // } | ||
| //} | ||
| // | ||
| //// Rewind goes back to the begining of the Iterator,ie. the index of the first data | ||
| //func (hmIt *HashMapIterator) Rewind() { | ||
| // hmIt.currIndex = 0 | ||
| //} | ||
| // | ||
| //// Seek finds a >= or <= target key according to the incoming key, | ||
| //// and starts traversing from this target key | ||
| //func (hmIt *HashMapIterator) Seek(key []byte) { | ||
| // if hmIt.reverse { | ||
| // hmIt.currIndex = sort.Search(len(hmIt.values), func(i int) bool { | ||
| // return bytes.Compare(hmIt.values[i].key, key) <= 0 | ||
| // }) | ||
| // } else { | ||
| // hmIt.currIndex = sort.Search(len(hmIt.values), func(i int) bool { | ||
| // return bytes.Compare(hmIt.values[i].key, key) >= 0 | ||
| // }) | ||
| // } | ||
| //} | ||
| // | ||
| //// Next jumps to the next key | ||
| //func (hmIt *HashMapIterator) Next() { | ||
| // hmIt.currIndex += 1 | ||
| //} | ||
| // | ||
| //// Valid refers to whether it is valid, that is, | ||
| //// whether all keys have been traversed, | ||
| //// used to exit the traverse ==> true->yes false-->no | ||
| //func (hmIt *HashMapIterator) Valid() bool { | ||
| // return hmIt.currIndex < len(hmIt.values) | ||
| //} | ||
| // | ||
| //// Key returns the key data at the current traversal position | ||
| //func (hmIt *HashMapIterator) Key() []byte { | ||
| // return hmIt.values[hmIt.currIndex].key | ||
| //} | ||
| // | ||
| //// Value returns the value data of the current traversal position | ||
| //func (hmIt *HashMapIterator) Value() *data.LogRecordPst { | ||
| // return hmIt.values[hmIt.currIndex].pst | ||
| //} | ||
| // | ||
| //// Close closes the iterator and releases the corresponding resources | ||
| //func (hmIt *HashMapIterator) Close() { | ||
| // hmIt.values = nil | ||
| //} |
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This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
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