Merge pull request #7616 from hercules-ci/fix-3898

Fix foreign key error inserting into NARs #3898

doc/manual/local.mk

@@ -51,13 +51,13 @@ $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli
 $(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix
 	@rm -rf $@
 	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-manpage.nix { toplevel = builtins.readFile $<; }'
-	# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
+	@# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
 	$(trace-gen) sed -i $@.tmp/*.md -e 's^@docroot@^../..^g'
 	@mv $@.tmp $@
 
 $(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/generate-options.nix $(d)/src/command-ref/conf-file-prefix.md $(bindir)/nix
 	@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp
-	# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
+	@# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-options.nix (builtins.fromJSON (builtins.readFile $<))' \
 	  | sed -e 's^@docroot@^..^g'>> $@.tmp
 	@mv $@.tmp $@
@@ -72,7 +72,7 @@ $(d)/conf-file.json: $(bindir)/nix
 
 $(d)/src/language/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix
 	@cat doc/manual/src/language/builtins-prefix.md > $@.tmp
-	# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
+	@# @docroot@: https://nixos.org/manual/nix/unstable/contributing/hacking.html#docroot-variable
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' \
 	  | sed -e 's^@docroot@^..^g' >> $@.tmp
 	@cat doc/manual/src/language/builtins-suffix.md >> $@.tmp

src/libstore/http-binary-cache-store.cc

@@ -56,7 +56,7 @@ public:
     void init() override
     {
         // FIXME: do this lazily?
-        if (auto cacheInfo = diskCache->cacheExists(cacheUri)) {
+        if (auto cacheInfo = diskCache->upToDateCacheExists(cacheUri)) {
             wantMassQuery.setDefault(cacheInfo->wantMassQuery);
             priority.setDefault(cacheInfo->priority);
         } else {

src/libstore/nar-info-disk-cache.cc

@@ -84,11 +84,10 @@ public:
 
     Sync<State> _state;
 
-    NarInfoDiskCacheImpl()
+    NarInfoDiskCacheImpl(Path dbPath = getCacheDir() + "/nix/binary-cache-v6.sqlite")
     {
         auto state(_state.lock());
 
-        Path dbPath = getCacheDir() + "/nix/binary-cache-v6.sqlite";
         createDirs(dirOf(dbPath));
 
         state->db = SQLite(dbPath);
@@ -98,7 +97,7 @@ public:
         state->db.exec(schema);
 
         state->insertCache.create(state->db,
-            "insert or replace into BinaryCaches(url, timestamp, storeDir, wantMassQuery, priority) values (?, ?, ?, ?, ?)");
+            "insert into BinaryCaches(url, timestamp, storeDir, wantMassQuery, priority) values (?1, ?2, ?3, ?4, ?5) on conflict (url) do update set timestamp = ?2, storeDir = ?3, wantMassQuery = ?4, priority = ?5 returning id;");
 
         state->queryCache.create(state->db,
             "select id, storeDir, wantMassQuery, priority from BinaryCaches where url = ? and timestamp > ?");
@@ -166,6 +165,8 @@ public:
         return i->second;
     }
 
+private:
+
     std::optional<Cache> queryCacheRaw(State & state, const std::string & uri)
     {
         auto i = state.caches.find(uri);
@@ -173,15 +174,21 @@ public:
             auto queryCache(state.queryCache.use()(uri)(time(0) - cacheInfoTtl));
             if (!queryCache.next())
                 return std::nullopt;
-            state.caches.emplace(uri,
-                Cache{(int) queryCache.getInt(0), queryCache.getStr(1), queryCache.getInt(2) != 0, (int) queryCache.getInt(3)});
+            auto cache = Cache {
+                .id = (int) queryCache.getInt(0),
+                .storeDir = queryCache.getStr(1),
+                .wantMassQuery = queryCache.getInt(2) != 0,
+                .priority = (int) queryCache.getInt(3),
+            };
+            state.caches.emplace(uri, cache);
         }
         return getCache(state, uri);
     }
 
-    void createCache(const std::string & uri, const Path & storeDir, bool wantMassQuery, int priority) override
+public:
+    int createCache(const std::string & uri, const Path & storeDir, bool wantMassQuery, int priority) override
     {
-        retrySQLite<void>([&]() {
+        return retrySQLite<int>([&]() {
             auto state(_state.lock());
             SQLiteTxn txn(state->db);
 
@@ -190,17 +197,29 @@ public:
             auto cache(queryCacheRaw(*state, uri));
 
             if (cache)
-                return;
+                return cache->id;
 
-            state->insertCache.use()(uri)(time(0))(storeDir)(wantMassQuery)(priority).exec();
-            assert(sqlite3_changes(state->db) == 1);
-            state->caches[uri] = Cache{(int) sqlite3_last_insert_rowid(state->db), storeDir, wantMassQuery, priority};
+            Cache ret {
+                .id = -1, // set below
+                .storeDir = storeDir,
+                .wantMassQuery = wantMassQuery,
+                .priority = priority,
+            };
+
+            {
+                auto r(state->insertCache.use()(uri)(time(0))(storeDir)(wantMassQuery)(priority));
+                assert(r.next());
+                ret.id = (int) r.getInt(0);
+            }
+
+            state->caches[uri] = ret;
 
             txn.commit();
+            return ret.id;
         });
     }
 
-    std::optional<CacheInfo> cacheExists(const std::string & uri) override
+    std::optional<CacheInfo> upToDateCacheExists(const std::string & uri) override
     {
         return retrySQLite<std::optional<CacheInfo>>([&]() -> std::optional<CacheInfo> {
             auto state(_state.lock());
@@ -208,6 +227,7 @@ public:
             if (!cache)
                 return std::nullopt;
             return CacheInfo {
+                .id = cache->id,
                 .wantMassQuery = cache->wantMassQuery,
                 .priority = cache->priority
             };
@@ -371,4 +391,9 @@ ref<NarInfoDiskCache> getNarInfoDiskCache()
     return cache;
 }
 
+ref<NarInfoDiskCache> getTestNarInfoDiskCache(Path dbPath)
+{
+    return make_ref<NarInfoDiskCacheImpl>(dbPath);
+}
+
 }

src/libstore/nar-info-disk-cache.hh

@@ -13,16 +13,17 @@ public:
 
     virtual ~NarInfoDiskCache() { }
 
-    virtual void createCache(const std::string & uri, const Path & storeDir,
+    virtual int createCache(const std::string & uri, const Path & storeDir,
         bool wantMassQuery, int priority) = 0;
 
     struct CacheInfo
     {
+        int id;
         bool wantMassQuery;
         int priority;
     };
 
-    virtual std::optional<CacheInfo> cacheExists(const std::string & uri) = 0;
+    virtual std::optional<CacheInfo> upToDateCacheExists(const std::string & uri) = 0;
 
     virtual std::pair<Outcome, std::shared_ptr<NarInfo>> lookupNarInfo(
         const std::string & uri, const std::string & hashPart) = 0;
@@ -45,4 +46,6 @@ public:
    multiple threads. */
 ref<NarInfoDiskCache> getNarInfoDiskCache();
 
+ref<NarInfoDiskCache> getTestNarInfoDiskCache(Path dbPath);
+
 }

src/libstore/s3-binary-cache-store.cc

@@ -238,7 +238,7 @@ struct S3BinaryCacheStoreImpl : virtual S3BinaryCacheStoreConfig, public virtual
 
     void init() override
     {
-        if (auto cacheInfo = diskCache->cacheExists(getUri())) {
+        if (auto cacheInfo = diskCache->upToDateCacheExists(getUri())) {
             wantMassQuery.setDefault(cacheInfo->wantMassQuery);
             priority.setDefault(cacheInfo->priority);
         } else {

src/libstore/sqlite.cc

@@ -41,6 +41,15 @@ SQLiteError::SQLiteError(const char *path, const char *errMsg, int errNo, int ex
         throw SQLiteError(path, errMsg, err, exterr, offset, std::move(hf));
 }
 
+static void traceSQL(void * x, const char * sql)
+{
+    // wacky delimiters:
+    //   so that we're quite unambiguous without escaping anything
+    // notice instead of trace:
+    //   so that this can be enabled without getting the firehose in our face.
+    notice("SQL<[%1%]>", sql);
+};
+
 SQLite::SQLite(const Path & path, bool create)
 {
     // useSQLiteWAL also indicates what virtual file system we need.  Using
@@ -58,6 +67,11 @@ SQLite::SQLite(const Path & path, bool create)
     if (sqlite3_busy_timeout(db, 60 * 60 * 1000) != SQLITE_OK)
         SQLiteError::throw_(db, "setting timeout");
 
+    if (getEnv("NIX_DEBUG_SQLITE_TRACES") == "1") {
+        // To debug sqlite statements; trace all of them
+        sqlite3_trace(db, &traceSQL, nullptr);
+    }
+
     exec("pragma foreign_keys = 1");
 }
 

src/libstore/tests/nar-info-disk-cache.cc

@@ -0,0 +1,123 @@
+#include "nar-info-disk-cache.hh"
+
+#include <gtest/gtest.h>
+#include <rapidcheck/gtest.h>
+#include "sqlite.hh"
+#include <sqlite3.h>
+
+
+namespace nix {
+
+TEST(NarInfoDiskCacheImpl, create_and_read) {
+    // This is a large single test to avoid some setup overhead.
+
+    int prio = 12345;
+    bool wantMassQuery = true;
+
+    Path tmpDir = createTempDir();
+    AutoDelete delTmpDir(tmpDir);
+    Path dbPath(tmpDir + "/test-narinfo-disk-cache.sqlite");
+
+    int savedId;
+    int barId;
+    SQLite db;
+    SQLiteStmt getIds;
+
+    {
+        auto cache = getTestNarInfoDiskCache(dbPath);
+
+        // Set up "background noise" and check that different caches receive different ids
+        {
+            auto bc1 = cache->createCache("https://bar", "/nix/storedir", wantMassQuery, prio);
+            auto bc2 = cache->createCache("https://xyz", "/nix/storedir", false, 12);
+            ASSERT_NE(bc1, bc2);
+            barId = bc1;
+        }
+
+        // Check that the fields are saved and returned correctly. This does not test
+        // the select statement yet, because of in-memory caching.
+        savedId = cache->createCache("http://foo", "/nix/storedir", wantMassQuery, prio);;
+        {
+            auto r = cache->upToDateCacheExists("http://foo");
+            ASSERT_TRUE(r);
+            ASSERT_EQ(r->priority, prio);
+            ASSERT_EQ(r->wantMassQuery, wantMassQuery);
+            ASSERT_EQ(savedId, r->id);
+        }
+
+        // We're going to pay special attention to the id field because we had a bug
+        // that changed it.
+        db = SQLite(dbPath);
+        getIds.create(db, "select id from BinaryCaches where url = 'http://foo'");
+
+        {
+            auto q(getIds.use());
+            ASSERT_TRUE(q.next());
+            ASSERT_EQ(savedId, q.getInt(0));
+            ASSERT_FALSE(q.next());
+        }
+
+        // Pretend that the caches are older, but keep one up to date, as "background noise"
+        db.exec("update BinaryCaches set timestamp = timestamp - 1 - 7 * 24 * 3600 where url <> 'https://xyz';");
+
+        // This shows that the in-memory cache works
+        {
+            auto r = cache->upToDateCacheExists("http://foo");
+            ASSERT_TRUE(r);
+            ASSERT_EQ(r->priority, prio);
+            ASSERT_EQ(r->wantMassQuery, wantMassQuery);
+        }
+    }
+
+    {
+        // We can't clear the in-memory cache, so we use a new cache object. This is
+        // more realistic anyway.
+        auto cache2 = getTestNarInfoDiskCache(dbPath);
+
+        {
+            auto r = cache2->upToDateCacheExists("http://foo");
+            ASSERT_FALSE(r);
+        }
+
+        // "Update", same data, check that the id number is reused
+        cache2->createCache("http://foo", "/nix/storedir", wantMassQuery, prio);
+
+        {
+            auto r = cache2->upToDateCacheExists("http://foo");
+            ASSERT_TRUE(r);
+            ASSERT_EQ(r->priority, prio);
+            ASSERT_EQ(r->wantMassQuery, wantMassQuery);
+            ASSERT_EQ(r->id, savedId);
+        }
+
+        {
+            auto q(getIds.use());
+            ASSERT_TRUE(q.next());
+            auto currentId = q.getInt(0);
+            ASSERT_FALSE(q.next());
+            ASSERT_EQ(currentId, savedId);
+        }
+
+        // Check that the fields can be modified, and the id remains the same
+        {
+            auto r0 = cache2->upToDateCacheExists("https://bar");
+            ASSERT_FALSE(r0);
+
+            cache2->createCache("https://bar", "/nix/storedir", !wantMassQuery, prio + 10);
+            auto r = cache2->upToDateCacheExists("https://bar");
+            ASSERT_EQ(r->wantMassQuery, !wantMassQuery);
+            ASSERT_EQ(r->priority, prio + 10);
+            ASSERT_EQ(r->id, barId);
+        }
+
+        // // Force update (no use case yet; we only retrieve cache metadata when stale based on timestamp)
+        // {
+        //     cache2->createCache("https://bar", "/nix/storedir", wantMassQuery, prio + 20);
+        //     auto r = cache2->upToDateCacheExists("https://bar");
+        //     ASSERT_EQ(r->wantMassQuery, wantMassQuery);
+        //     ASSERT_EQ(r->priority, prio + 20);
+        // }
+    }
+}
+
+}