lix/src/libstore/sqlite.hh
John Ericson 0746951be1
Finish converting existing comments for internal API docs (#8146)
* Finish converting existing comments for internal API docs

99% of this was just reformatting existing comments. Only two exceptions:

- Expanded upon `BuildResult::status` compat note

- Split up file-level `symbol-table.hh` doc comments to get
  per-definition docs

Also fixed a few whitespace goofs, turning leading tabs to spaces and
removing trailing spaces.

Picking up from #8133

* Fix two things from comments

* Use triple-backtick not indent for `dumpPath`

* Convert GNU-style `\`..'` quotes to markdown style in API docs

This will render correctly.
2023-04-07 13:55:28 +00:00

161 lines
3.4 KiB
C++

#pragma once
///@file
#include <functional>
#include <string>
#include "error.hh"
struct sqlite3;
struct sqlite3_stmt;
namespace nix {
/**
* RAII wrapper to close a SQLite database automatically.
*/
struct SQLite
{
sqlite3 * db = 0;
SQLite() { }
SQLite(const Path & path, bool create = true);
SQLite(const SQLite & from) = delete;
SQLite& operator = (const SQLite & from) = delete;
SQLite& operator = (SQLite && from) { db = from.db; from.db = 0; return *this; }
~SQLite();
operator sqlite3 * () { return db; }
/**
* Disable synchronous mode, set truncate journal mode.
*/
void isCache();
void exec(const std::string & stmt);
uint64_t getLastInsertedRowId();
};
/**
* RAII wrapper to create and destroy SQLite prepared statements.
*/
struct SQLiteStmt
{
sqlite3 * db = 0;
sqlite3_stmt * stmt = 0;
std::string sql;
SQLiteStmt() { }
SQLiteStmt(sqlite3 * db, const std::string & sql) { create(db, sql); }
void create(sqlite3 * db, const std::string & s);
~SQLiteStmt();
operator sqlite3_stmt * () { return stmt; }
/**
* Helper for binding / executing statements.
*/
class Use
{
friend struct SQLiteStmt;
private:
SQLiteStmt & stmt;
unsigned int curArg = 1;
Use(SQLiteStmt & stmt);
public:
~Use();
/**
* Bind the next parameter.
*/
Use & operator () (std::string_view value, bool notNull = true);
Use & operator () (const unsigned char * data, size_t len, bool notNull = true);
Use & operator () (int64_t value, bool notNull = true);
Use & bind(); // null
int step();
/**
* Execute a statement that does not return rows.
*/
void exec();
/**
* For statements that return 0 or more rows. Returns true iff
* a row is available.
*/
bool next();
std::string getStr(int col);
int64_t getInt(int col);
bool isNull(int col);
};
Use use()
{
return Use(*this);
}
};
/**
* RAII helper that ensures transactions are aborted unless explicitly
* committed.
*/
struct SQLiteTxn
{
bool active = false;
sqlite3 * db;
SQLiteTxn(sqlite3 * db);
void commit();
~SQLiteTxn();
};
struct SQLiteError : Error
{
std::string path;
std::string errMsg;
int errNo, extendedErrNo, offset;
template<typename... Args>
[[noreturn]] static void throw_(sqlite3 * db, const std::string & fs, const Args & ... args) {
throw_(db, hintfmt(fs, args...));
}
SQLiteError(const char *path, const char *errMsg, int errNo, int extendedErrNo, int offset, hintformat && hf);
protected:
template<typename... Args>
SQLiteError(const char *path, const char *errMsg, int errNo, int extendedErrNo, int offset, const std::string & fs, const Args & ... args)
: SQLiteError(path, errNo, extendedErrNo, offset, hintfmt(fs, args...))
{ }
[[noreturn]] static void throw_(sqlite3 * db, hintformat && hf);
};
MakeError(SQLiteBusy, SQLiteError);
void handleSQLiteBusy(const SQLiteBusy & e);
/**
* Convenience function for retrying a SQLite transaction when the
* database is busy.
*/
template<typename T, typename F>
T retrySQLite(F && fun)
{
while (true) {
try {
return fun();
} catch (SQLiteBusy & e) {
handleSQLiteBusy(e);
}
}
}
}