Merge pull request #4282 from tweag/fix-ca-hash-rewriting

fix the hash rewriting for ca-derivations
This commit is contained in:
John Ericson 2023-06-14 18:25:00 +02:00 committed by GitHub
commit 61a3e1f2e2
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8 changed files with 196 additions and 108 deletions

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@ -6,7 +6,7 @@
#include "globals.hh"
#include "json-to-value.hh"
#include "names.hh"
#include "references.hh"
#include "path-references.hh"
#include "store-api.hh"
#include "util.hh"
#include "value-to-json.hh"

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@ -4,7 +4,7 @@
#include "worker.hh"
#include "builtins.hh"
#include "builtins/buildenv.hh"
#include "references.hh"
#include "path-references.hh"
#include "finally.hh"
#include "util.hh"
#include "archive.hh"
@ -2394,18 +2394,21 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
continue;
auto references = *referencesOpt;
auto rewriteOutput = [&]() {
auto rewriteOutput = [&](const StringMap & rewrites) {
/* Apply hash rewriting if necessary. */
if (!outputRewrites.empty()) {
if (!rewrites.empty()) {
debug("rewriting hashes in '%1%'; cross fingers", actualPath);
/* FIXME: this is in-memory. */
StringSink sink;
dumpPath(actualPath, sink);
/* FIXME: Is this actually streaming? */
auto source = sinkToSource([&](Sink & nextSink) {
RewritingSink rsink(rewrites, nextSink);
dumpPath(actualPath, rsink);
rsink.flush();
});
Path tmpPath = actualPath + ".tmp";
restorePath(tmpPath, *source);
deletePath(actualPath);
sink.s = rewriteStrings(sink.s, outputRewrites);
StringSource source(sink.s);
restorePath(actualPath, source);
movePath(tmpPath, actualPath);
/* FIXME: set proper permissions in restorePath() so
we don't have to do another traversal. */
@ -2454,7 +2457,7 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
"since recursive hashing is not enabled (one of outputHashMode={flat,text} is true)",
actualPath);
}
rewriteOutput();
rewriteOutput(outputRewrites);
/* FIXME optimize and deduplicate with addToStore */
std::string oldHashPart { scratchPath->hashPart() };
HashModuloSink caSink { outputHash.hashType, oldHashPart };
@ -2492,16 +2495,14 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
Hash::dummy,
};
if (*scratchPath != newInfo0.path) {
// Also rewrite the output path
auto source = sinkToSource([&](Sink & nextSink) {
RewritingSink rsink2(oldHashPart, std::string(newInfo0.path.hashPart()), nextSink);
dumpPath(actualPath, rsink2);
rsink2.flush();
});
Path tmpPath = actualPath + ".tmp";
restorePath(tmpPath, *source);
deletePath(actualPath);
movePath(tmpPath, actualPath);
// If the path has some self-references, we need to rewrite
// them.
// (note that this doesn't invalidate the ca hash we calculated
// above because it's computed *modulo the self-references*, so
// it already takes this rewrite into account).
rewriteOutput(
StringMap{{oldHashPart,
std::string(newInfo0.path.hashPart())}});
}
HashResult narHashAndSize = hashPath(htSHA256, actualPath);
@ -2523,7 +2524,7 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
outputRewrites.insert_or_assign(
std::string { scratchPath->hashPart() },
std::string { requiredFinalPath.hashPart() });
rewriteOutput();
rewriteOutput(outputRewrites);
auto narHashAndSize = hashPath(htSHA256, actualPath);
ValidPathInfo newInfo0 { requiredFinalPath, narHashAndSize.first };
newInfo0.narSize = narHashAndSize.second;

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@ -0,0 +1,73 @@
#include "path-references.hh"
#include "hash.hh"
#include "util.hh"
#include "archive.hh"
#include <map>
#include <cstdlib>
#include <mutex>
#include <algorithm>
namespace nix {
PathRefScanSink::PathRefScanSink(StringSet && hashes, std::map<std::string, StorePath> && backMap)
: RefScanSink(std::move(hashes))
, backMap(std::move(backMap))
{ }
PathRefScanSink PathRefScanSink::fromPaths(const StorePathSet & refs)
{
StringSet hashes;
std::map<std::string, StorePath> backMap;
for (auto & i : refs) {
std::string hashPart(i.hashPart());
auto inserted = backMap.emplace(hashPart, i).second;
assert(inserted);
hashes.insert(hashPart);
}
return PathRefScanSink(std::move(hashes), std::move(backMap));
}
StorePathSet PathRefScanSink::getResultPaths()
{
/* Map the hashes found back to their store paths. */
StorePathSet found;
for (auto & i : getResult()) {
auto j = backMap.find(i);
assert(j != backMap.end());
found.insert(j->second);
}
return found;
}
std::pair<StorePathSet, HashResult> scanForReferences(
const std::string & path,
const StorePathSet & refs)
{
HashSink hashSink { htSHA256 };
auto found = scanForReferences(hashSink, path, refs);
auto hash = hashSink.finish();
return std::pair<StorePathSet, HashResult>(found, hash);
}
StorePathSet scanForReferences(
Sink & toTee,
const Path & path,
const StorePathSet & refs)
{
PathRefScanSink refsSink = PathRefScanSink::fromPaths(refs);
TeeSink sink { refsSink, toTee };
/* Look for the hashes in the NAR dump of the path. */
dumpPath(path, sink);
return refsSink.getResultPaths();
}
}

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@ -0,0 +1,25 @@
#pragma once
#include "references.hh"
#include "path.hh"
namespace nix {
std::pair<StorePathSet, HashResult> scanForReferences(const Path & path, const StorePathSet & refs);
StorePathSet scanForReferences(Sink & toTee, const Path & path, const StorePathSet & refs);
class PathRefScanSink : public RefScanSink
{
std::map<std::string, StorePath> backMap;
PathRefScanSink(StringSet && hashes, std::map<std::string, StorePath> && backMap);
public:
static PathRefScanSink fromPaths(const StorePathSet & refs);
StorePathSet getResultPaths();
};
}

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@ -6,6 +6,7 @@
#include <map>
#include <cstdlib>
#include <mutex>
#include <algorithm>
namespace nix {
@ -66,69 +67,20 @@ void RefScanSink::operator () (std::string_view data)
}
PathRefScanSink::PathRefScanSink(StringSet && hashes, std::map<std::string, StorePath> && backMap)
: RefScanSink(std::move(hashes))
, backMap(std::move(backMap))
{ }
PathRefScanSink PathRefScanSink::fromPaths(const StorePathSet & refs)
{
StringSet hashes;
std::map<std::string, StorePath> backMap;
for (auto & i : refs) {
std::string hashPart(i.hashPart());
auto inserted = backMap.emplace(hashPart, i).second;
assert(inserted);
hashes.insert(hashPart);
}
return PathRefScanSink(std::move(hashes), std::move(backMap));
}
StorePathSet PathRefScanSink::getResultPaths()
{
/* Map the hashes found back to their store paths. */
StorePathSet found;
for (auto & i : getResult()) {
auto j = backMap.find(i);
assert(j != backMap.end());
found.insert(j->second);
}
return found;
}
std::pair<StorePathSet, HashResult> scanForReferences(
const std::string & path,
const StorePathSet & refs)
{
HashSink hashSink { htSHA256 };
auto found = scanForReferences(hashSink, path, refs);
auto hash = hashSink.finish();
return std::pair<StorePathSet, HashResult>(found, hash);
}
StorePathSet scanForReferences(
Sink & toTee,
const Path & path,
const StorePathSet & refs)
{
PathRefScanSink refsSink = PathRefScanSink::fromPaths(refs);
TeeSink sink { refsSink, toTee };
/* Look for the hashes in the NAR dump of the path. */
dumpPath(path, sink);
return refsSink.getResultPaths();
}
RewritingSink::RewritingSink(const std::string & from, const std::string & to, Sink & nextSink)
: from(from), to(to), nextSink(nextSink)
: RewritingSink({{from, to}}, nextSink)
{
}
RewritingSink::RewritingSink(const StringMap & rewrites, Sink & nextSink)
: rewrites(rewrites), nextSink(nextSink)
{
long unsigned int maxRewriteSize = 0;
for (auto & [from, to] : rewrites) {
assert(from.size() == to.size());
maxRewriteSize = std::max(maxRewriteSize, from.size());
}
this->maxRewriteSize = maxRewriteSize;
}
void RewritingSink::operator () (std::string_view data)
@ -136,13 +88,13 @@ void RewritingSink::operator () (std::string_view data)
std::string s(prev);
s.append(data);
size_t j = 0;
while ((j = s.find(from, j)) != std::string::npos) {
matches.push_back(pos + j);
s.replace(j, from.size(), to);
}
s = rewriteStrings(s, rewrites);
prev = s.size() < from.size() ? s : std::string(s, s.size() - from.size() + 1, from.size() - 1);
prev = s.size() < maxRewriteSize
? s
: maxRewriteSize == 0
? ""
: std::string(s, s.size() - maxRewriteSize + 1, maxRewriteSize - 1);
auto consumed = s.size() - prev.size();

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@ -2,14 +2,9 @@
///@file
#include "hash.hh"
#include "path.hh"
namespace nix {
std::pair<StorePathSet, HashResult> scanForReferences(const Path & path, const StorePathSet & refs);
StorePathSet scanForReferences(Sink & toTee, const Path & path, const StorePathSet & refs);
class RefScanSink : public Sink
{
StringSet hashes;
@ -28,28 +23,18 @@ public:
void operator () (std::string_view data) override;
};
class PathRefScanSink : public RefScanSink
{
std::map<std::string, StorePath> backMap;
PathRefScanSink(StringSet && hashes, std::map<std::string, StorePath> && backMap);
public:
static PathRefScanSink fromPaths(const StorePathSet & refs);
StorePathSet getResultPaths();
};
struct RewritingSink : Sink
{
std::string from, to, prev;
const StringMap rewrites;
long unsigned int maxRewriteSize;
std::string prev;
Sink & nextSink;
uint64_t pos = 0;
std::vector<uint64_t> matches;
RewritingSink(const std::string & from, const std::string & to, Sink & nextSink);
RewritingSink(const StringMap & rewrites, Sink & nextSink);
void operator () (std::string_view data) override;

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@ -0,0 +1,46 @@
#include "references.hh"
#include <gtest/gtest.h>
namespace nix {
using std::string;
struct RewriteParams {
string originalString, finalString;
StringMap rewrites;
friend std::ostream& operator<<(std::ostream& os, const RewriteParams& bar) {
StringSet strRewrites;
for (auto & [from, to] : bar.rewrites)
strRewrites.insert(from + "->" + to);
return os <<
"OriginalString: " << bar.originalString << std::endl <<
"Rewrites: " << concatStringsSep(",", strRewrites) << std::endl <<
"Expected result: " << bar.finalString;
}
};
class RewriteTest : public ::testing::TestWithParam<RewriteParams> {
};
TEST_P(RewriteTest, IdentityRewriteIsIdentity) {
RewriteParams param = GetParam();
StringSink rewritten;
auto rewriter = RewritingSink(param.rewrites, rewritten);
rewriter(param.originalString);
rewriter.flush();
ASSERT_EQ(rewritten.s, param.finalString);
}
INSTANTIATE_TEST_CASE_P(
references,
RewriteTest,
::testing::Values(
RewriteParams{ "foooo", "baroo", {{"foo", "bar"}, {"bar", "baz"}}},
RewriteParams{ "foooo", "bazoo", {{"fou", "bar"}, {"foo", "baz"}}},
RewriteParams{ "foooo", "foooo", {}}
)
);
}

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@ -5,6 +5,12 @@ enableFeatures "fetch-closure"
clearStore
clearCacheCache
# Old daemons don't properly zero out the self-references when
# calculating the CA hashes, so this breaks `nix store
# make-content-addressed` which expects the client and the daemon to
# compute the same hash
requireDaemonNewerThan "2.16.0pre20230524"
# Initialize binary cache.
nonCaPath=$(nix build --json --file ./dependencies.nix --no-link | jq -r .[].outputs.out)
caPath=$(nix store make-content-addressed --json $nonCaPath | jq -r '.rewrites | map(.) | .[]')