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authorEelco Dolstra <eelco.dolstra@logicblox.com>2012-07-18T14·47-0400
committerEelco Dolstra <eelco.dolstra@logicblox.com>2012-07-18T14·47-0400
commitfe241ece2932492866693d268d02a7912e766ac7 (patch)
tree2cb24a4d45f563e32946bf34d878969bd05263ec /src/libstore/local-store.cc
parenta6f348599c94d8a5f7b41c7d8e43658dc6407be7 (diff)
parentccc52adfb2121ade510d35dc9b91193af9fa731e (diff)
Merge branch 'master' into no-manifests
Diffstat (limited to 'src/libstore/local-store.cc')
-rw-r--r--src/libstore/local-store.cc24
1 files changed, 24 insertions, 0 deletions
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 6e4cd053c859..aa21774df4a7 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -405,6 +405,10 @@ void LocalStore::openDB(bool create)
         "select v.id, v.path from DerivationOutputs d join ValidPaths v on d.drv = v.id where d.path = ?;");
     stmtQueryDerivationOutputs.create(db,
         "select id, path from DerivationOutputs where drv = ?;");
+    // Use "path >= ?" with limit 1 rather than "path like '?%'" to
+    // ensure efficient lookup.
+    stmtQueryPathFromHashPart.create(db,
+        "select path from ValidPaths where path >= ? limit 1;");
 }
 
 
@@ -874,6 +878,26 @@ StringSet LocalStore::queryDerivationOutputNames(const Path & path)
 }
 
 
+Path LocalStore::queryPathFromHashPart(const string & hashPart)
+{
+    if (hashPart.size() != 32) throw Error("invalid hash part");
+    
+    SQLiteTxn txn(db);
+
+    Path prefix = nixStore + "/" + hashPart;
+    
+    SQLiteStmtUse use(stmtQueryPathFromHashPart);
+    stmtQueryPathFromHashPart.bind(prefix);
+
+    int res = sqlite3_step(stmtQueryPathFromHashPart);
+    if (res == SQLITE_DONE) return "";
+    if (res != SQLITE_ROW) throwSQLiteError(db, "finding path in database");
+
+    const char * s = (const char *) sqlite3_column_text(stmtQueryPathFromHashPart, 0);
+    return s && prefix.compare(0, prefix.size(), s, prefix.size()) == 0 ? s : "";
+}
+
+
 void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter & run)
 {
     if (run.pid != -1) return;