49 lines
1.4 KiB
Go
49 lines
1.4 KiB
Go
/*
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Package rollinghash implements rolling versions of some hashes
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*/
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package rollinghash
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import "hash"
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// DefaultWindowCap is the default capacity of the internal window of a
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// new Hash.
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const DefaultWindowCap = 64
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// A Roller is a type that has the method Roll. Roll updates the hash of a
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// rolling window from just the entering byte. You MUST call Write()
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// BEFORE using this method and provide it with an initial window of size
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// at least 1 byte. You can then call this method for every new byte
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// entering the window. The byte leaving the window is automatically
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// computed from a copy of the window internally kept in the checksum.
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// This window is updated along with the internal state of the checksum
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// every time Roll() is called.
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type Roller interface {
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Roll(b byte)
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}
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// rollinghash.Hash extends hash.Hash by adding the method Roll. A
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// rollinghash.Hash can be updated byte by byte, by specifying which byte
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// enters the window.
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type Hash interface {
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hash.Hash
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Roller
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}
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// rollinghash.Hash32 extends hash.Hash by adding the method Roll. A
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// rollinghash.Hash32 can be updated byte by byte, by specifying which
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// byte enters the window.
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type Hash32 interface {
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hash.Hash32
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Roller
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}
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// rollinghash.Hash64 extends hash.Hash by adding the method Roll. A
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// rollinghash.Hash64 can be updated byte by byte, by specifying which
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// byte enters the window.
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type Hash64 interface {
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hash.Hash64
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Roller
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}
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