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Diffstat (limited to 'nix/libutil/hash.hh')
-rw-r--r-- | nix/libutil/hash.hh | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/nix/libutil/hash.hh b/nix/libutil/hash.hh new file mode 100644 index 0000000000..8f099c4f07 --- /dev/null +++ b/nix/libutil/hash.hh @@ -0,0 +1,113 @@ +#pragma once + +#include "types.hh" +#include "serialise.hh" + + +namespace nix { + + +typedef enum { htUnknown, htMD5, htSHA1, htSHA256 } HashType; + + +const int md5HashSize = 16; +const int sha1HashSize = 20; +const int sha256HashSize = 32; + +extern const string base32Chars; + + +struct Hash +{ + static const unsigned int maxHashSize = 32; + unsigned int hashSize; + unsigned char hash[maxHashSize]; + + HashType type; + + /* Create an unusable hash object. */ + Hash(); + + /* Create a zero-filled hash object. */ + Hash(HashType type); + + /* Check whether two hash are equal. */ + bool operator == (const Hash & h2) const; + + /* Check whether two hash are not equal. */ + bool operator != (const Hash & h2) const; + + /* For sorting. */ + bool operator < (const Hash & h) const; +}; + + +/* Convert a hash to a hexadecimal representation. */ +string printHash(const Hash & hash); + +/* Parse a hexadecimal representation of a hash code. */ +Hash parseHash(HashType ht, const string & s); + +/* Returns the length of a base-32 hash representation. */ +unsigned int hashLength32(const Hash & hash); + +/* Convert a hash to a base-32 representation. */ +string printHash32(const Hash & hash); + +/* Print a hash in base-16 if it's MD5, or base-32 otherwise. */ +string printHash16or32(const Hash & hash); + +/* Parse a base-32 representation of a hash code. */ +Hash parseHash32(HashType ht, const string & s); + +/* Parse a base-16 or base-32 representation of a hash code. */ +Hash parseHash16or32(HashType ht, const string & s); + +/* Verify that the given string is a valid hash code. */ +bool isHash(const string & s); + +/* Compute the hash of the given string. */ +Hash hashString(HashType ht, const string & s); + +/* Compute the hash of the given file. */ +Hash hashFile(HashType ht, const Path & path); + +/* Compute the hash of the given path. The hash is defined as + (essentially) hashString(ht, dumpPath(path)). */ +struct PathFilter; +extern PathFilter defaultPathFilter; +typedef std::pair<Hash, unsigned long long> HashResult; +HashResult hashPath(HashType ht, const Path & path, + PathFilter & filter = defaultPathFilter); + +/* Compress a hash to the specified number of bytes by cyclically + XORing bytes together. */ +Hash compressHash(const Hash & hash, unsigned int newSize); + +/* Parse a string representing a hash type. */ +HashType parseHashType(const string & s); + +/* And the reverse. */ +string printHashType(HashType ht); + + +struct Ctx; + +class HashSink : public BufferedSink +{ +private: + HashType ht; + Ctx * ctx; + unsigned long long bytes; + +public: + HashSink(HashType ht); + HashSink(const HashSink & h); + ~HashSink(); + void write(const unsigned char * data, size_t len); + HashResult finish(); + HashResult currentHash(); +}; + + +} |