84 lines
1.7 KiB
C++
84 lines
1.7 KiB
C++
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#pragma once
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#include <functional>
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#include <string>
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#include "types.hh"
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class sqlite3;
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class sqlite3_stmt;
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namespace nix {
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/* RAII wrapper to close a SQLite database automatically. */
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struct SQLite
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{
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sqlite3 * db;
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SQLite() { db = 0; }
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~SQLite();
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operator sqlite3 * () { return db; }
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};
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/* RAII wrapper to create and destroy SQLite prepared statements. */
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struct SQLiteStmt
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{
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sqlite3 * db;
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sqlite3_stmt * stmt;
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unsigned int curArg;
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SQLiteStmt() { stmt = 0; }
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void create(sqlite3 * db, const std::string & s);
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void reset();
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~SQLiteStmt();
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operator sqlite3_stmt * () { return stmt; }
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void bind(const std::string & value);
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void bind(int value);
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void bind64(long long value);
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void bind();
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};
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/* Helper class to ensure that prepared statements are reset when
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leaving the scope that uses them. Unfinished prepared statements
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prevent transactions from being aborted, and can cause locks to be
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kept when they should be released. */
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struct SQLiteStmtUse
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{
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SQLiteStmt & stmt;
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SQLiteStmtUse(SQLiteStmt & stmt);
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~SQLiteStmtUse();
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};
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/* RAII helper that ensures transactions are aborted unless explicitly
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committed. */
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struct SQLiteTxn
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{
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bool active = false;
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sqlite3 * db;
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SQLiteTxn(sqlite3 * db);
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void commit();
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~SQLiteTxn();
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};
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MakeError(SQLiteError, Error);
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MakeError(SQLiteBusy, SQLiteError);
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[[noreturn]] void throwSQLiteError(sqlite3 * db, const format & f);
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/* Convenience function for retrying a SQLite transaction when the
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database is busy. */
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template<typename T>
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T retrySQLite(std::function<T()> fun)
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{
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while (true) {
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try {
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return fun();
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} catch (SQLiteBusy & e) {
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}
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}
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}
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}
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