| Stability | provisional |
|---|---|
| Portability | portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Digest.Adler32
Description
An implementation of the Adler-32 checksum algorithm. There are two ways to use this module:
adler32andadler32Updatewhich useWord32for checksums,adler32'andadler32Update'which use the abstract typeAdler32for checksums. This mode is slightly more low-level (extractAdler32has to be used to obtain aWord32for the checksum), but it supports some additional operations such rolling checksum and compounding.
- class Adler32Src a where
- data Adler32
- extractAdler32 :: Adler32 -> Word32
- makeAdler32 :: Integral a => Word32 -> a -> Adler32
- adler32SlideL :: Word8 -> Adler32 -> Word8 -> Adler32
- adler32SlideR :: Word8 -> Adler32 -> Word8 -> Adler32
- adler32AppendByte :: Adler32 -> Word8 -> Adler32
- adler32UnAppendByte :: Adler32 -> Word8 -> Adler32
- adler32PrependByte :: Word8 -> Adler32 -> Adler32
- adler32UnPrependByte :: Word8 -> Adler32 -> Adler32
- adler32UnAppend :: Adler32 -> Adler32 -> Adler32
- adler32UnPrepend :: Adler32 -> Adler32 -> Adler32
Documentation
class Adler32Src a where #
Types of messages for which the Adler-32 checksum can be computed.
Minimal complete definition
Methods
Compute the Adler-32 checksum of a ByteString.
adler32Update :: Word32 -> a -> Word32 #
Update the checksum of a message by providing a ByteString to be
appended to the original message.
adler32Update' :: Adler32 -> a -> Adler32 #
Instances
An abstract representation of an Adler-32 checksum. Forcing a value of this type to whnf will cause it to be evaluated completely.
extractAdler32 :: Adler32 -> Word32 #
Extract the actual Adler-32 checksum from a Adler32 object.
makeAdler32 :: Integral a => Word32 -> a -> Adler32 #
makeAdler32 c l will create an Adler32 object that corresponds to
a message whose checksum is c and length is l.
adler32SlideL :: Word8 -> Adler32 -> Word8 -> Adler32 #
O(1). If c is the checksum of a message that starts with the
byte d1 then adler32SlideL d1 c d2 is the checksum of the message
that is obtained by removing the first byte and appending the byte d2
at the end of the original message. It is the caller's responsibility to
ensure that the original message starts with the byte d1.
adler32SlideR :: Word8 -> Adler32 -> Word8 -> Adler32 #
O(1). Similar to adler32SlideL except that it slides the checksum
window to the other direction, i.e. in adler32SlideR d1 c d2 the byte
d2 will be removed from the end of the original message and the byte
d1 will be prepended to its beginning. It is the caller's responsibility
to ensure that the original message ends with the byte d2.
adler32AppendByte :: Adler32 -> Word8 -> Adler32 #
O(1). Given the checksum of a message, this function returns the checksum of that message with a byte appended to it.
adler32UnAppendByte :: Adler32 -> Word8 -> Adler32 #
O(1). Given the checksum of a message, this function returns the checksum of that message its last byte removed from it. The value of that byte has to be provided by the caller and the behavior of the function is unspecified if that value is incorrect.
adler32PrependByte :: Word8 -> Adler32 -> Adler32 #
O(1). Given the checksum of a message, this function returns the checksum of that message with a byte prepended to it.
adler32UnPrependByte :: Word8 -> Adler32 -> Adler32 #
O(1). Given the checksum of a message, this function returns the checksum of that message its first byte removed from it. The value of that byte has to be provided by the caller and the behavior of the function is unspecified if that value is incorrect.
adler32UnAppend :: Adler32 -> Adler32 -> Adler32 #
O(1). If s1 and s2 are two messages then adler32UnAppend c c2
returns the checksum of s1 where c is the checksum of s1 <> s2 and
c2 is the checksum of s2.
adler32UnPrepend :: Adler32 -> Adler32 -> Adler32 #
O(1). If s1 and s2 are two messages then adler32UnAppend c1 c
returns the checksum of s2 where c is the checksum of s1 <> s2 and
c1 is the checksum of s1.