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-rw-r--r--nix/libutil/hash.hh113
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diff --git a/nix/libutil/hash.hh b/nix/libutil/hash.hh
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+#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();
+};
+
+
+}