1 files changed, 195 insertions, 0 deletions
diff --git a/third_party/nix/src/libstore/sqlite.cc b/third_party/nix/src/libstore/sqlite.cc
new file mode 100644
index 000000000000..2dea952d0275
--- /dev/null
+++ b/third_party/nix/src/libstore/sqlite.cc
@@ -0,0 +1,195 @@
+#include "sqlite.hh"
+
+#include <atomic>
+
+#include <glog/logging.h>
+#include <sqlite3.h>
+
+#include "util.hh"
+
+namespace nix {
+
+[[noreturn]] void throwSQLiteError(sqlite3* db, const FormatOrString& fs) {
+  int err = sqlite3_errcode(db);
+  int exterr = sqlite3_extended_errcode(db);
+
+  auto path = sqlite3_db_filename(db, nullptr);
+  if (path == nullptr) {
+    path = "(in-memory)";
+  }
+
+  if (err == SQLITE_BUSY || err == SQLITE_PROTOCOL) {
+    throw SQLiteBusy(
+        err == SQLITE_PROTOCOL
+            ? fmt("SQLite database '%s' is busy (SQLITE_PROTOCOL)", path)
+            : fmt("SQLite database '%s' is busy", path));
+  }
+  throw SQLiteError("%s: %s (in '%s')", fs.s, sqlite3_errstr(exterr), path);
+}
+
+SQLite::SQLite(const Path& path) {
+  if (sqlite3_open_v2(path.c_str(), &db,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
+                      nullptr) != SQLITE_OK) {
+    throw Error(format("cannot open SQLite database '%s'") % path);
+  }
+}
+
+SQLite::~SQLite() {
+  try {
+    if ((db != nullptr) && sqlite3_close(db) != SQLITE_OK) {
+      throwSQLiteError(db, "closing database");
+    }
+  } catch (...) {
+    ignoreException();
+  }
+}
+
+void SQLite::exec(const std::string& stmt) {
+  retrySQLite<void>([&]() {
+    if (sqlite3_exec(db, stmt.c_str(), nullptr, nullptr, nullptr) !=
+        SQLITE_OK) {
+      throwSQLiteError(db, format("executing SQLite statement '%s'") % stmt);
+    }
+  });
+}
+
+void SQLiteStmt::create(sqlite3* db, const string& sql) {
+  checkInterrupt();
+  assert(!stmt);
+  if (sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr) != SQLITE_OK) {
+    throwSQLiteError(db, fmt("creating statement '%s'", sql));
+  }
+  this->db = db;
+  this->sql = sql;
+}
+
+SQLiteStmt::~SQLiteStmt() {
+  try {
+    if ((stmt != nullptr) && sqlite3_finalize(stmt) != SQLITE_OK) {
+      throwSQLiteError(db, fmt("finalizing statement '%s'", sql));
+    }
+  } catch (...) {
+    ignoreException();
+  }
+}
+
+SQLiteStmt::Use::Use(SQLiteStmt& stmt) : stmt(stmt) {
+  assert(stmt.stmt);
+  /* Note: sqlite3_reset() returns the error code for the most
+     recent call to sqlite3_step().  So ignore it. */
+  sqlite3_reset(stmt);
+}
+
+SQLiteStmt::Use::~Use() { sqlite3_reset(stmt); }
+
+SQLiteStmt::Use& SQLiteStmt::Use::operator()(const std::string& value,
+                                             bool notNull) {
+  if (notNull) {
+    if (sqlite3_bind_text(stmt, curArg++, value.c_str(), -1,
+                          SQLITE_TRANSIENT) != SQLITE_OK) {
+      throwSQLiteError(stmt.db, "binding argument");
+    }
+  } else {
+    bind();
+  }
+  return *this;
+}
+
+SQLiteStmt::Use& SQLiteStmt::Use::operator()(int64_t value, bool notNull) {
+  if (notNull) {
+    if (sqlite3_bind_int64(stmt, curArg++, value) != SQLITE_OK) {
+      throwSQLiteError(stmt.db, "binding argument");
+    }
+  } else {
+    bind();
+  }
+  return *this;
+}
+
+SQLiteStmt::Use& SQLiteStmt::Use::bind() {
+  if (sqlite3_bind_null(stmt, curArg++) != SQLITE_OK) {
+    throwSQLiteError(stmt.db, "binding argument");
+  }
+  return *this;
+}
+
+int SQLiteStmt::Use::step() { return sqlite3_step(stmt); }
+
+void SQLiteStmt::Use::exec() {
+  int r = step();
+  assert(r != SQLITE_ROW);
+  if (r != SQLITE_DONE) {
+    throwSQLiteError(stmt.db, fmt("executing SQLite statement '%s'", stmt.sql));
+  }
+}
+
+bool SQLiteStmt::Use::next() {
+  int r = step();
+  if (r != SQLITE_DONE && r != SQLITE_ROW) {
+    throwSQLiteError(stmt.db, fmt("executing SQLite query '%s'", stmt.sql));
+  }
+  return r == SQLITE_ROW;
+}
+
+std::string SQLiteStmt::Use::getStr(int col) {
+  auto s = (const char*)sqlite3_column_text(stmt, col);
+  assert(s);
+  return s;
+}
+
+int64_t SQLiteStmt::Use::getInt(int col) {
+  // FIXME: detect nulls?
+  return sqlite3_column_int64(stmt, col);
+}
+
+bool SQLiteStmt::Use::isNull(int col) {
+  return sqlite3_column_type(stmt, col) == SQLITE_NULL;
+}
+
+SQLiteTxn::SQLiteTxn(sqlite3* db) {
+  this->db = db;
+  if (sqlite3_exec(db, "begin;", nullptr, nullptr, nullptr) != SQLITE_OK) {
+    throwSQLiteError(db, "starting transaction");
+  }
+  active = true;
+}
+
+void SQLiteTxn::commit() {
+  if (sqlite3_exec(db, "commit;", nullptr, nullptr, nullptr) != SQLITE_OK) {
+    throwSQLiteError(db, "committing transaction");
+  }
+  active = false;
+}
+
+SQLiteTxn::~SQLiteTxn() {
+  try {
+    if (active &&
+        sqlite3_exec(db, "rollback;", nullptr, nullptr, nullptr) != SQLITE_OK) {
+      throwSQLiteError(db, "aborting transaction");
+    }
+  } catch (...) {
+    ignoreException();
+  }
+}
+
+void handleSQLiteBusy(const SQLiteBusy& e) {
+  static std::atomic<time_t> lastWarned{0};
+
+  time_t now = time(nullptr);
+
+  if (now > lastWarned + 10) {
+    lastWarned = now;
+    LOG(ERROR) << e.what();
+  }
+
+  /* Sleep for a while since retrying the transaction right away
+     is likely to fail again. */
+  checkInterrupt();
+  struct timespec t;
+  t.tv_sec = 0;
+  t.tv_nsec = (random() % 100) * 1000 * 1000; /* <= 0.1s */
+  nanosleep(&t, nullptr);
+}
+
+}  // namespace nix