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Simplify printHash32

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This commit is contained in:
Eelco Dolstra 2015-02-03 18:35:11 +01:00
parent 3688db3d43
commit db2ec59903
1 changed files with 16 additions and 34 deletions
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50
src/libutil/hash.cc
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@ -84,7 +84,7 @@ string printHash(const Hash & hash)
return string(buf, hash.hashSize * 2); return string(buf, hash.hashSize * 2);
} }
Hash parseHash(HashType ht, const string & s) Hash parseHash(HashType ht, const string & s)
{ {
Hash hash(ht); Hash hash(ht);
@ -92,7 +92,7 @@ Hash parseHash(HashType ht, const string & s)
throw Error(format("invalid hash ‘%1%’") % s); throw Error(format("invalid hash ‘%1%’") % s);
for (unsigned int i = 0; i < hash.hashSize; i++) { for (unsigned int i = 0; i < hash.hashSize; i++) {
string s2(s, i * 2, 2); string s2(s, i * 2, 2);
if (!isxdigit(s2[0]) || !isxdigit(s2[1])) if (!isxdigit(s2[0]) || !isxdigit(s2[1]))
throw Error(format("invalid hash ‘%1%’") % s); throw Error(format("invalid hash ‘%1%’") % s);
std::istringstream str(s2); std::istringstream str(s2);
int n; int n;
@ -103,24 +103,6 @@ Hash parseHash(HashType ht, const string & s)
} }
static unsigned char divMod(unsigned char * bytes, unsigned char y)
{
unsigned int borrow = 0;
int pos = Hash::maxHashSize - 1;
while (pos >= 0 && !bytes[pos]) --pos;
for ( ; pos >= 0; --pos) {
unsigned int s = bytes[pos] + (borrow << 8);
unsigned int d = s / y;
borrow = s % y;
bytes[pos] = d;
}
return borrow;
}
unsigned int hashLength32(const Hash & hash) unsigned int hashLength32(const Hash & hash)
{ {
return (hash.hashSize * 8 - 1) / 5 + 1; return (hash.hashSize * 8 - 1) / 5 + 1;
@ -136,19 +118,19 @@ string printHash32(const Hash & hash)
Hash hash2(hash); Hash hash2(hash);
unsigned int len = hashLength32(hash); unsigned int len = hashLength32(hash);
const char * chars = base32Chars.data(); string s;
s.reserve(len);
string s(len, '0');
int pos = len - 1; for (int n = len - 1; n >= 0; n--) {
while (pos >= 0) { unsigned int b = n * 5;
unsigned char digit = divMod(hash2.hash, 32); unsigned int i = b / 8;
s[pos--] = chars[digit]; unsigned int j = b % 8;
unsigned char c =
(hash.hash[i] >> j)
| (i >= hash.hashSize - 1 ? 0 : hash.hash[i + 1] << (8 - j));
s.push_back(base32Chars[c & 0x1f]);
} }
for (unsigned int i = 0; i < hash2.maxHashSize; ++i)
assert(hash2.hash[i] == 0);
return s; return s;
} }
@ -299,7 +281,7 @@ Hash hashFile(HashType ht, const Path & path)
if (n == -1) throw SysError(format("reading file ‘%1%’") % path); if (n == -1) throw SysError(format("reading file ‘%1%’") % path);
update(ht, ctx, buf, n); update(ht, ctx, buf, n);
} }
finish(ht, ctx, hash.hash); finish(ht, ctx, hash.hash);
return hash; return hash;
} }
@ -311,7 +293,7 @@ HashSink::HashSink(HashType ht) : ht(ht)
bytes = 0; bytes = 0;
start(ht, *ctx); start(ht, *ctx);
} }
HashSink::~HashSink() HashSink::~HashSink()
{ {
bufPos = 0; bufPos = 0;
@ -369,7 +351,7 @@ HashType parseHashType(const string & s)
else return htUnknown; else return htUnknown;
} }
string printHashType(HashType ht) string printHashType(HashType ht)
{ {
if (ht == htMD5) return "md5"; if (ht == htMD5) return "md5";
@ -378,5 +360,5 @@ string printHashType(HashType ht)
else throw Error("cannot print unknown hash type"); else throw Error("cannot print unknown hash type");
} }
} }