4 #ifndef DBALLE_SQL_POSTGRESQL_H 5 #define DBALLE_SQL_POSTGRESQL_H 12 #include <unordered_set> 29 const char* what()
const noexcept
override {
return msg.c_str(); }
35 namespace postgresql {
37 int64_t encode_datetime(
const Datetime& arg);
38 int64_t encode_int64_t(int64_t arg);
41 template<
typename... ARGS>
struct Params 43 static const int count =
sizeof...(ARGS);
44 const char* args[
sizeof...(ARGS)];
45 int lengths[
sizeof...(ARGS)];
46 int formats[
sizeof...(ARGS)];
47 void* local[
sizeof...(ARGS)];
49 Params(
const ARGS&... args)
71 template<
typename... REST>
72 void _add(
unsigned pos, std::nullptr_t arg,
const REST&... rest)
78 _add(pos + 1, rest...);
82 template<
typename... REST>
83 void _add(
unsigned pos, int32_t arg,
const REST&... rest)
85 local[pos] = malloc(
sizeof(int32_t));
86 *(int32_t*)local[pos] = (int32_t)htonl((uint32_t)arg);
87 args[pos] = (
const char*)local[pos];
88 lengths[pos] =
sizeof(int32_t);
90 _add(pos + 1, rest...);
94 template<
typename... REST>
95 void _add(
unsigned pos, uint64_t arg,
const REST&... rest)
97 local[pos] = malloc(
sizeof(int64_t));
98 *(int64_t*)local[pos] = encode_int64_t(arg);
99 args[pos] = (
const char*)local[pos];
100 lengths[pos] =
sizeof(int64_t);
102 _add(pos + 1, rest...);
106 template<
typename... REST>
107 void _add(
unsigned pos,
const char* arg,
const REST&... rest)
109 local[pos] =
nullptr;
113 _add(pos + 1, rest...);
117 template<
typename... REST>
118 void _add(
unsigned pos,
const std::string& arg,
const REST&... rest)
120 local[pos] =
nullptr;
121 args[pos] = arg.data();
122 lengths[pos] = arg.size();
124 _add(pos + 1, rest...);
128 template<
typename... REST>
129 void _add(
unsigned pos,
const std::vector<uint8_t>& arg,
const REST&... rest)
131 local[pos] =
nullptr;
132 args[pos] = (
const char*)arg.data();
133 lengths[pos] = arg.size();
135 _add(pos + 1, rest...);
139 template<
typename... REST>
142 local[pos] = malloc(
sizeof(int64_t));
143 *(int64_t*)local[pos] = encode_datetime(arg);
144 args[pos] = (
const char*)local[pos];
145 lengths[pos] =
sizeof(int64_t);
147 _add(pos + 1, rest...);
156 Result() : res(
nullptr) {}
157 Result(PGresult* res) : res(res) {}
158 ~
Result() { PQclear(res); }
164 if (
this == &o)
return *
this;
171 operator bool()
const {
return res !=
nullptr; }
172 operator PGresult*() {
return res; }
173 operator const PGresult*()
const {
return res; }
188 unsigned rowcount()
const {
return PQntuples(res); }
191 bool is_null(
unsigned row,
unsigned col)
const 193 return PQgetisnull(res, row, col);
199 char* val = PQgetvalue(res, row, col);
204 uint16_t
get_int2(
unsigned row,
unsigned col)
const 206 char* val = PQgetvalue(res, row, col);
207 return ntohs(*(uint16_t*)val);
211 uint32_t
get_int4(
unsigned row,
unsigned col)
const 213 char* val = PQgetvalue(res, row, col);
214 return ntohl(*(uint32_t*)val);
218 uint64_t
get_int8(
unsigned row,
unsigned col)
const;
221 std::vector<uint8_t>
get_bytea(
unsigned row,
unsigned col)
const;
226 return PQgetvalue(res, row, col);
245 PGconn*
db =
nullptr;
246 std::unordered_set<std::string> prepared_names;
251 void init_after_connect();
255 void fork_prepare()
override;
256 void fork_parent()
override;
257 void fork_child()
override;
259 void check_connection();
268 static std::shared_ptr<PostgreSQLConnection> create();
270 operator PGconn*() {
return db; }
278 void open_url(
const std::string& connection_string);
281 std::unique_ptr<Transaction>
transaction(
bool readonly=
false)
override;
284 void prepare(
const std::string& name,
const std::string& query);
289 auto res = PQexecParams(
db, query, 0,
nullptr,
nullptr,
nullptr,
nullptr, 1);
295 postgresql::Result exec_unchecked(
const std::string& query)
298 auto res = PQexecParams(
db, query.c_str(), 0,
nullptr,
nullptr,
nullptr,
nullptr, 1);
300 throw error_postgresql(
db,
"cannot execute query " + query);
304 template<
typename STRING>
305 void exec_no_data(STRING query)
307 postgresql::Result res(exec_unchecked(query));
308 res.expect_no_data(query);
311 template<
typename STRING>
312 postgresql::Result exec(STRING query)
314 postgresql::Result res(exec_unchecked(query));
315 res.expect_result(query);
319 template<
typename STRING>
320 postgresql::Result exec_one_row(STRING query)
322 postgresql::Result res(exec_unchecked(query));
323 res.expect_one_row(query);
327 template<
typename ...ARGS>
328 postgresql::Result exec_unchecked(
const char* query, ARGS... args)
331 postgresql::Params<ARGS...> params(args...);
332 auto res = PQexecParams(
db, query, params.count,
nullptr, params.args, params.lengths, params.formats, 1);
334 throw error_postgresql(
db, std::string(
"cannot execute query ") + query);
338 template<
typename ...ARGS>
339 postgresql::Result exec_unchecked(
const std::string& query, ARGS... args)
342 postgresql::Params<ARGS...> params(args...);
343 auto res = PQexecParams(
db, query.c_str(), params.count,
nullptr, params.args, params.lengths, params.formats, 1);
345 throw error_postgresql(
db,
"cannot execute query " + query);
349 template<
typename STRING,
typename ...ARGS>
350 void exec_no_data(STRING query, ARGS... args)
352 postgresql::Result res(exec_unchecked(query, args...));
353 res.expect_no_data(query);
356 template<
typename STRING,
typename ...ARGS>
357 postgresql::Result exec(STRING query, ARGS... args)
359 postgresql::Result res(exec_unchecked(query, args...));
360 res.expect_result(query);
364 template<
typename STRING,
typename ...ARGS>
365 postgresql::Result exec_one_row(STRING query, ARGS... args)
367 postgresql::Result res(exec_unchecked(query, args...));
368 res.expect_one_row(query);
372 postgresql::Result exec_prepared_unchecked(
const char* name)
375 auto res = PQexecPrepared(
db, name, 0,
nullptr,
nullptr,
nullptr, 1);
377 throw error_postgresql(
db, std::string(
"cannot execute prepared query ") + name);
381 postgresql::Result exec_prepared_unchecked(
const std::string& name)
384 auto res = PQexecPrepared(
db, name.c_str(), 0,
nullptr,
nullptr,
nullptr, 1);
386 throw error_postgresql(
db,
"cannot execute prepared query " + name);
390 template<
typename STRING>
391 void exec_prepared_no_data(STRING name)
393 postgresql::Result res(exec_prepared_unchecked(name));
394 res.expect_no_data(name);
397 template<
typename STRING>
398 postgresql::Result exec_prepared(STRING name)
400 postgresql::Result res(exec_prepared_unchecked(name));
401 res.expect_result(name);
405 template<
typename STRING>
406 postgresql::Result exec_prepared_one_row(STRING name)
408 postgresql::Result res(exec_prepared_unchecked(name));
409 res.expect_one_row(name);
413 template<
typename ...ARGS>
414 postgresql::Result exec_prepared_unchecked(
const char* name, ARGS... args)
416 postgresql::Params<ARGS...> params(args...);
417 return PQexecPrepared(
db, name, params.count, params.args, params.lengths, params.formats, 1);
420 template<
typename ...ARGS>
421 postgresql::Result exec_prepared_unchecked(
const std::string& name, ARGS... args)
423 postgresql::Params<ARGS...> params(args...);
424 return PQexecPrepared(
db, name.c_str(), params.count, params.args, params.lengths, params.formats, 1);
427 template<
typename STRING,
typename ...ARGS>
428 void exec_prepared_no_data(STRING name, ARGS... args)
430 postgresql::Result res(exec_prepared_unchecked(name, args...));
431 res.expect_no_data(name);
434 template<
typename STRING,
typename ...ARGS>
435 postgresql::Result exec_prepared(STRING name, ARGS... args)
437 postgresql::Result res(exec_prepared_unchecked(name, args...));
438 res.expect_result(name);
442 template<
typename STRING,
typename ...ARGS>
443 postgresql::Result exec_prepared_one_row(STRING name, ARGS... args)
445 postgresql::Result res(exec_prepared_unchecked(name, args...));
446 res.expect_one_row(name);
460 void execute(const
std::
string& query) override;
461 void explain(const
std::
string& query, FILE* out) override;
void open_url(const std::string &connection_string)
Connect to PostgreSQL using a connection URI.
Database connection.
Definition: postgresql.h:241
Result(Result &&o)
Implement move.
Definition: postgresql.h:161
void set_setting(const std::string &key, const std::string &value) override
Set a value in the settings table.
Argument list for PQexecParams built at compile time.
Definition: postgresql.h:41
void _add(unsigned pos, const char *arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:107
void _add(unsigned pos, uint64_t arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:95
void run_single_row_mode(const std::string &query_desc, std::function< void(const postgresql::Result &)> dest)
Retrieve query results in single row mode.
bool forked
Marker to catch attempts to reuse connections in forked processes.
Definition: postgresql.h:248
int changes()
Count the number of rows modified by the last query that was run.
void cancel_running_query_nothrow() noexcept
Send a cancellation command to the server.
bool has_table(const std::string &name) override
Check if the database contains a table.
unsigned rowcount() const
Get the number of rows in the result.
Definition: postgresql.h:188
void _add(unsigned pos)
Terminating condition for compile-time arg expansion.
Definition: postgresql.h:66
void _add(unsigned pos, const std::vector< uint8_t > &arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:129
uint16_t get_int2(unsigned row, unsigned col) const
Return a result value, transmitted in binary as a 2 bit integer.
Definition: postgresql.h:204
void prepare(const std::string &name, const std::string &query)
Precompile a query.
bool is_null(unsigned row, unsigned col) const
Check if a result value is null.
Definition: postgresql.h:191
std::vector< uint8_t > get_bytea(unsigned row, unsigned col) const
Return a result value, transmitted in binary as an 8 bit integer.
uint32_t get_int4(unsigned row, unsigned col) const
Return a result value, transmitted in binary as a 4 bit integer.
Definition: postgresql.h:211
void pqexec(const std::string &query)
Wrap PQexec.
Datetime get_timestamp(unsigned row, unsigned col) const
Return a result value, transmitted as a timestamp without timezone.
void pqexec_nothrow(const std::string &query) noexcept
Wrap PQexec but do not throw an exception in case of errors.
void expect_one_row(const std::string &query)
Check that the result successfully returned one row of data.
Wrap a PGresult, taking care of its memory management.
Definition: postgresql.h:152
bool get_bool(unsigned row, unsigned col) const
Return a result value, transmitted in binary as a byte (?)
Definition: postgresql.h:197
void _add(unsigned pos, int32_t arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:83
void append_escaped(Querybuf &qb, const char *str)
Escape the string as a literal value and append it to qb.
void expect_result(const std::string &query)
Check that the result successfully returned some (possibly empty) data.
void expect_no_data(const std::string &query)
Check that the result successfully returned no data.
void drop_table_if_exists(const char *name)
Delete a table in the database if it exists, otherwise do nothing.
Report an PostgreSQL error.
Definition: postgresql.h:20
Common infrastructure for talking with SQL databases.
Error in case of failed database operations.
Definition: error.h:21
void _add(unsigned pos, const std::string &arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:118
PGconn * db
Database connection.
Definition: postgresql.h:245
void discard_all_input_nothrow() noexcept
Discard all input from an asynchronous request.
void _add(unsigned pos, const Datetime &arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:140
void explain(const std::string &query, FILE *out) override
Format and print the EXPLAIN output for the query to the given file.
Date and time.
Definition: types.h:164
std::unique_ptr< Transaction > transaction(bool readonly=false) override
Begin a transaction.
void drop_settings() override
Drop the settings table.
#define WREPORT_THROWF_ATTRS(a, b)
void _add(unsigned pos, std::nullptr_t arg, const REST &... rest)
Fill in the argument structures.
Definition: postgresql.h:72
const char * get_string(unsigned row, unsigned col) const
Return a result value, transmitted as a string.
Definition: postgresql.h:224
uint64_t get_int8(unsigned row, unsigned col) const
Return a result value, transmitted in binary as an 8 bit integer.
void execute(const std::string &query) override
Execute a query without reading its results.
std::string get_setting(const std::string &key) override
Get a value from the settings table.
void expect_success(const std::string &query)
Check that the result was successful.