lix/src/libstore/sqlite.cc
Eelco Dolstra 451ebf24ce Cache path info lookups in SQLite
This re-implements the binary cache database in C++, allowing it to be
used by other Store backends, in particular the S3 backend.
2016-04-20 14:12:38 +02:00

173 lines
4 KiB
C++

#include "sqlite.hh"
#include "util.hh"
#include <sqlite3.h>
namespace nix {
[[noreturn]] void throwSQLiteError(sqlite3 * db, const format & f)
{
int err = sqlite3_errcode(db);
if (err == SQLITE_BUSY || err == SQLITE_PROTOCOL) {
if (err == SQLITE_PROTOCOL)
printMsg(lvlError, "warning: SQLite database is busy (SQLITE_PROTOCOL)");
else {
static bool warned = false;
if (!warned) {
printMsg(lvlError, "warning: SQLite database is busy");
warned = true;
}
}
/* Sleep for a while since retrying the transaction right away
is likely to fail again. */
checkInterrupt();
#if HAVE_NANOSLEEP
struct timespec t;
t.tv_sec = 0;
t.tv_nsec = (random() % 100) * 1000 * 1000; /* <= 0.1s */
nanosleep(&t, 0);
#else
sleep(1);
#endif
throw SQLiteBusy(format("%1%: %2%") % f.str() % sqlite3_errmsg(db));
}
else
throw SQLiteError(format("%1%: %2%") % f.str() % sqlite3_errmsg(db));
}
SQLite::~SQLite()
{
try {
if (db && sqlite3_close(db) != SQLITE_OK)
throwSQLiteError(db, "closing database");
} catch (...) {
ignoreException();
}
}
void SQLiteStmt::create(sqlite3 * db, const string & s)
{
checkInterrupt();
assert(!stmt);
if (sqlite3_prepare_v2(db, s.c_str(), -1, &stmt, 0) != SQLITE_OK)
throwSQLiteError(db, "creating statement");
this->db = db;
}
SQLiteStmt::~SQLiteStmt()
{
try {
if (stmt && sqlite3_finalize(stmt) != SQLITE_OK)
throwSQLiteError(db, "finalizing statement");
} 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, "executing SQLite statement");
}
bool SQLiteStmt::Use::next()
{
int r = step();
if (r != SQLITE_DONE && r != SQLITE_ROW)
throwSQLiteError(stmt.db, "executing SQLite query");
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;", 0, 0, 0) != SQLITE_OK)
throwSQLiteError(db, "starting transaction");
active = true;
}
void SQLiteTxn::commit()
{
if (sqlite3_exec(db, "commit;", 0, 0, 0) != SQLITE_OK)
throwSQLiteError(db, "committing transaction");
active = false;
}
SQLiteTxn::~SQLiteTxn()
{
try {
if (active && sqlite3_exec(db, "rollback;", 0, 0, 0) != SQLITE_OK)
throwSQLiteError(db, "aborting transaction");
} catch (...) {
ignoreException();
}
}
}