ml
51 lines
895 B
Go
51 lines
895 B
Go
package compression
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type dictEntry struct {
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prev *dictEntry
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depth int
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next [256]*dictEntry
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key Word
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value byte
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first byte
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used bool
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}
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func rootDictEntry() *dictEntry {
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return &dictEntry{prev: nil, depth: 0, value: 0x00, key: Reset}
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}
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var emptyList [256]*dictEntry
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func (entry *dictEntry) Add(value byte, key Word, newEntry *dictEntry) *dictEntry {
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newEntry.prev = entry
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newEntry.depth = entry.depth + 1
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newEntry.value = value
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newEntry.key = key
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newEntry.first = entry.first
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if newEntry.used {
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copy(newEntry.next[:], emptyList[:])
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}
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newEntry.used = true
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entry.next[value] = newEntry
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if entry.depth == 0 {
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newEntry.first = value
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}
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return newEntry
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}
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func (entry *dictEntry) Data(bytes []byte) {
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cur := entry
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for i := entry.depth - 1; i >= 0; i-- {
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bytes[i] = cur.value
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cur = cur.prev
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}
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}
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func (entry *dictEntry) FirstByte() byte {
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return entry.first
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}
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