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Sink: Use std::string_view

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This commit is contained in:
Eelco Dolstra 2020-12-02 14:00:43 +01:00
parent aa68486112
commit faa31f4084
21 changed files with 182 additions and 211 deletions
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50
src/libstore/references.cc
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@ -55,27 +55,23 @@ struct RefScanSink : Sink
RefScanSink() { }
void operator () (const unsigned char * data, size_t len);
void operator () (std::string_view data) override
{
/* It's possible that a reference spans the previous and current
fragment, so search in the concatenation of the tail of the
previous fragment and the start of the current fragment. */
string s = tail + std::string(data, 0, refLength);
search((const unsigned char *) s.data(), s.size(), hashes, seen);
search((const unsigned char *) data.data(), data.size(), hashes, seen);
size_t tailLen = data.size() <= refLength ? data.size() : refLength;
tail = std::string(tail, tail.size() < refLength - tailLen ? 0 : tail.size() - (refLength - tailLen));
tail.append({data.data() + data.size() - tailLen, tailLen});
}
};
void RefScanSink::operator () (const unsigned char * data, size_t len)
{
/* It's possible that a reference spans the previous and current
fragment, so search in the concatenation of the tail of the
previous fragment and the start of the current fragment. */
string s = tail + string((const char *) data, len > refLength ? refLength : len);
search((const unsigned char *) s.data(), s.size(), hashes, seen);
search(data, len, hashes, seen);
size_t tailLen = len <= refLength ? len : refLength;
tail =
string(tail, tail.size() < refLength - tailLen ? 0 : tail.size() - (refLength - tailLen)) +
string((const char *) data + len - tailLen, tailLen);
}
std::pair<PathSet, HashResult> scanForReferences(const string & path,
const PathSet & refs)
{
@ -129,10 +125,10 @@ RewritingSink::RewritingSink(const std::string & from, const std::string & to, S
assert(from.size() == to.size());
}
void RewritingSink::operator () (const unsigned char * data, size_t len)
void RewritingSink::operator () (std::string_view data)
{
std::string s(prev);
s.append((const char *) data, len);
s.append(data);
size_t j = 0;
while ((j = s.find(from, j)) != string::npos) {
@ -146,14 +142,14 @@ void RewritingSink::operator () (const unsigned char * data, size_t len)
pos += consumed;
if (consumed) nextSink((unsigned char *) s.data(), consumed);
if (consumed) nextSink(s.substr(0, consumed));
}
void RewritingSink::flush()
{
if (prev.empty()) return;
pos += prev.size();
nextSink((unsigned char *) prev.data(), prev.size());
nextSink(prev);
prev.clear();
}
@ -163,9 +159,9 @@ HashModuloSink::HashModuloSink(HashType ht, const std::string & modulus)
{
}
void HashModuloSink::operator () (const unsigned char * data, size_t len)
void HashModuloSink::operator () (std::string_view data)
{
rewritingSink(data, len);
rewritingSink(data);
}
HashResult HashModuloSink::finish()
@ -176,10 +172,8 @@ HashResult HashModuloSink::finish()
NAR with self-references and a NAR with some of the
self-references already zeroed out do not produce a hash
collision. FIXME: proof. */
for (auto & pos : rewritingSink.matches) {
auto s = fmt("|%d", pos);
hashSink((unsigned char *) s.data(), s.size());
}
for (auto & pos : rewritingSink.matches)
hashSink(fmt("|%d", pos));
auto h = hashSink.finish();
return {h.first, rewritingSink.pos};