pg: avoid leaking a PGconn on connection errors (#6543)

pull/6474/head
Leonardo Cecchi 2020-10-03 07:03:11 +02:00 committed by GitHub
parent c8a884f57f
commit 8ac0bd44bd
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 52 additions and 31 deletions

View File

@ -6,7 +6,6 @@ module pg
#flag windows -I @VROOT/thirdparty/pg/include
#flag windows -L @VROOT/thirdparty/pg/win64
#include <libpq-fe.h>
pub struct DB {
mut:
conn &C.PGconn
@ -17,7 +16,8 @@ pub mut:
vals []string
}
struct C.PGResult { }
struct C.PGResult {
}
pub struct Config {
pub:
@ -29,37 +29,58 @@ pub:
}
fn C.PQconnectdb(a byteptr) &C.PGconn
fn C.PQerrorMessage(voidptr) byteptr
fn C.PQgetvalue(voidptr, int, int) byteptr
fn C.PQstatus(voidptr) int
fn C.PQntuples(voidptr) int
fn C.PQnfields(voidptr) int
fn C.PQexec(voidptr) voidptr
fn C.PQexecParams(voidptr) voidptr
fn C.PQclear(voidptr) voidptr
fn C.PQfinish(voidptr)
fn C.PQerrorMessage(arg_1 voidptr) byteptr
fn C.PQgetvalue(arg_1 voidptr, arg_2, arg_3 int) byteptr
fn C.PQstatus(arg_1 voidptr) int
fn C.PQntuples(arg_1 voidptr) int
fn C.PQnfields(arg_1 voidptr) int
fn C.PQexec(arg_1 voidptr) voidptr
fn C.PQexecParams(arg_1 voidptr) voidptr
fn C.PQclear(arg_1 voidptr) voidptr
fn C.PQfinish(arg_1 voidptr)
// Makes a new connection to the database server using
// the parameters from the `Config` structure, returning
// a connection error when something goes wrong
pub fn connect(config Config) ?DB {
conninfo := 'host=$config.host port=$config.port user=$config.user dbname=$config.dbname password=$config.password'
conn := C.PQconnectdb(conninfo.str)
status := C.PQstatus(conn)
println("status=$status")
if status != C.CONNECTION_OK {
error_msg := C.PQerrorMessage(conn)
return error ('Connection to a PG database failed: ' + unsafe { error_msg.vstring() } )
if conn == 0 {
return error('libpq memory allocation error')
}
status := C.PQstatus(conn)
if status != C.CONNECTION_OK {
// We force the construction of a new string as the
// error message will be freed by the next `PQfinish`
// call
c_error_msg := unsafe {C.PQerrorMessage(conn).vstring()}
error_msg := '$c_error_msg'
C.PQfinish(conn)
return error('Connection to a PG database failed: $error_msg')
}
return DB{
conn: conn
}
return DB {conn: conn}
}
fn res_to_rows(res voidptr) []Row {
nr_rows := C.PQntuples(res)
nr_cols := C.PQnfields(res)
mut rows := []Row{}
for i in 0..nr_rows {
for i in 0 .. nr_rows {
mut row := Row{}
for j in 0..nr_cols {
for j in 0 .. nr_cols {
val := C.PQgetvalue(res, i, j)
sval := unsafe { val.vstring() }
sval := unsafe {val.vstring()}
row.vals << sval
}
rows << row
@ -107,7 +128,7 @@ pub fn (db DB) q_strings(query string) []Row {
pub fn (db DB) exec(query string) []Row {
res := C.PQexec(db.conn, query.str)
e := unsafe { C.PQerrorMessage(db.conn).vstring() }
e := unsafe {C.PQerrorMessage(db.conn).vstring()}
if e != '' {
println('pg exec error:')
println(e)
@ -125,11 +146,11 @@ fn rows_first_or_empty(rows []Row) ?Row {
pub fn (db DB) exec_one(query string) ?Row {
res := C.PQexec(db.conn, query.str)
e := unsafe { C.PQerrorMessage(db.conn).vstring() }
e := unsafe {C.PQerrorMessage(db.conn).vstring()}
if e != '' {
return error('pg exec error: "$e"')
}
row := rows_first_or_empty( res_to_rows(res) )?
row := rows_first_or_empty(res_to_rows(res)) ?
return row
}
@ -138,7 +159,7 @@ pub fn (db DB) exec_one(query string) ?Row {
pub fn (db DB) exec_param_many(query string, params []string) []Row {
unsafe {
mut param_vals := &byteptr(malloc(params.len * 8))
for i in 0..params.len {
for i in 0 .. params.len {
param_vals[i] = params[i].str
}
res := C.PQexecParams(db.conn, query.str, params.len, 0, param_vals, 0, 0, 0)
@ -147,7 +168,7 @@ pub fn (db DB) exec_param_many(query string, params []string) []Row {
}
}
pub fn (db DB) exec_param2(query string, param, param2 string) []Row {
pub fn (db DB) exec_param2(query, param, param2 string) []Row {
mut param_vals := [2]byteptr{}
param_vals[0] = param.str
param_vals[1] = param2.str
@ -155,7 +176,7 @@ pub fn (db DB) exec_param2(query string, param, param2 string) []Row {
return db.handle_error_or_result(res, 'exec_param2')
}
pub fn (db DB) exec_param(query string, param string) []Row {
pub fn (db DB) exec_param(query, param string) []Row {
mut param_vals := [1]byteptr{}
param_vals[0] = param.str
res := C.PQexecParams(db.conn, query.str, 1, 0, param_vals, 0, 0, 0)
@ -163,7 +184,7 @@ pub fn (db DB) exec_param(query string, param string) []Row {
}
fn (db DB) handle_error_or_result(res voidptr, elabel string) []Row {
e := unsafe { C.PQerrorMessage(db.conn).vstring() }
e := unsafe {C.PQerrorMessage(db.conn).vstring()}
if e != '' {
println('pg $elabel error:')
println(e)