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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/old/vlib/pg/pg.v | |
download | cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.gz cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.bz2 cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.zip |
Diffstat (limited to 'v_windows/v/old/vlib/pg/pg.v')
-rw-r--r-- | v_windows/v/old/vlib/pg/pg.v | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/v_windows/v/old/vlib/pg/pg.v b/v_windows/v/old/vlib/pg/pg.v new file mode 100644 index 0000000..9e2d7e7 --- /dev/null +++ b/v_windows/v/old/vlib/pg/pg.v @@ -0,0 +1,277 @@ +module pg + +import io + +#flag -lpq +#flag linux -I/usr/include/postgresql +#flag darwin -I/opt/local/include/postgresql11 +#flag windows -I @VEXEROOT/thirdparty/pg/include +#flag windows -L @VEXEROOT/thirdparty/pg/win64 + +// PostgreSQL Source Code +// https://doxygen.postgresql.org/libpq-fe_8h.html +#include <libpq-fe.h> +// for orm +#include <arpa/inet.h> + +pub struct DB { +mut: + conn &C.PGconn +} + +pub struct Row { +pub mut: + vals []string +} + +struct C.PGResult { +} + +pub struct Config { +pub: + host string + port int = 5432 + user string + password string + dbname string +} + +fn C.PQconnectdb(a &byte) &C.PGconn + +fn C.PQerrorMessage(voidptr) &byte + +fn C.PQgetvalue(&C.PGResult, int, int) &byte + +fn C.PQstatus(voidptr) int + +fn C.PQresultStatus(voidptr) int + +fn C.PQntuples(&C.PGResult) int + +fn C.PQnfields(&C.PGResult) int + +fn C.PQexec(voidptr, &byte) &C.PGResult + +// Params: +// const Oid *paramTypes +// const char *const *paramValues +// const int *paramLengths +// const int *paramFormats +fn C.PQexecParams(conn voidptr, command &byte, nParams int, paramTypes int, paramValues &byte, paramLengths int, paramFormats int, resultFormat int) &C.PGResult + +fn C.PQputCopyData(conn voidptr, buffer &byte, nbytes int) int + +fn C.PQputCopyEnd(voidptr, &byte) int + +fn C.PQgetCopyData(conn voidptr, buffer &&byte, async int) int + +fn C.PQclear(&C.PGResult) voidptr + +fn C.PQfreemem(voidptr) + +fn C.PQfinish(voidptr) + +// connect 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=$config.password' + conn := C.PQconnectdb(conninfo.str) + if conn == 0 { + return error('libpq memory allocation error') + } + status := C.PQstatus(conn) + if status != C.CONNECTION_OK { + // We force the construction of a new string as the + // error message will be freed by the next `PQfinish` + // call + c_error_msg := unsafe { C.PQerrorMessage(conn).vstring() } + error_msg := '$c_error_msg' + C.PQfinish(conn) + return error('Connection to a PG database failed: $error_msg') + } + return DB{ + conn: conn + } +} + +fn res_to_rows(res voidptr) []Row { + nr_rows := C.PQntuples(res) + nr_cols := C.PQnfields(res) + + mut rows := []Row{} + for i in 0 .. nr_rows { + mut row := Row{} + for j in 0 .. nr_cols { + val := C.PQgetvalue(res, i, j) + sval := unsafe { val.vstring() } + row.vals << sval + } + rows << row + } + + C.PQclear(res) + return rows +} + +// close frees the underlying resource allocated by the database connection +pub fn (db DB) close() { + C.PQfinish(db.conn) +} + +// q_int submit a command to the database server and +// returns an the first field in the first tuple +// converted to an int. If no row is found or on +// command failure, an error is returned +pub fn (db DB) q_int(query string) ?int { + rows := db.exec(query) ? + if rows.len == 0 { + return error('q_int "$query" not found') + } + row := rows[0] + if row.vals.len == 0 { + return 0 + } + val := row.vals[0] + return val.int() +} + +// q_string submit a command to the database server and +// returns an the first field in the first tuple +// as a string. If no row is found or on +// command failure, an error is returned +pub fn (db DB) q_string(query string) ?string { + rows := db.exec(query) ? + if rows.len == 0 { + return error('q_string "$query" not found') + } + row := rows[0] + if row.vals.len == 0 { + return '' + } + val := row.vals[0] + return val +} + +// q_strings submit a command to the database server and +// returns the resulting row set. Alias of `exec` +pub fn (db DB) q_strings(query string) ?[]Row { + return db.exec(query) +} + +// exec submit a command to the database server and wait +// for the result, returning an error on failure and a +// row set on success +pub fn (db DB) exec(query string) ?[]Row { + res := C.PQexec(db.conn, query.str) + return db.handle_error_or_result(res, 'exec') +} + +fn rows_first_or_empty(rows []Row) ?Row { + if rows.len == 0 { + return error('no row') + } + return rows[0] +} + +pub fn (db DB) exec_one(query string) ?Row { + res := C.PQexec(db.conn, query.str) + e := unsafe { C.PQerrorMessage(db.conn).vstring() } + if e != '' { + return error('pg exec error: "$e"') + } + row := rows_first_or_empty(res_to_rows(res)) ? + return row +} + +// exec_param_many executes a query with the provided parameters +pub fn (db DB) exec_param_many(query string, params []string) ?[]Row { + mut param_vals := []&char{len: 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.data, 0, 0, 0) + return db.handle_error_or_result(res, 'exec_param_many') +} + +pub fn (db DB) exec_param2(query string, param string, param2 string) ?[]Row { + return db.exec_param_many(query, [param, param2]) +} + +pub fn (db DB) exec_param(query string, param string) ?[]Row { + return db.exec_param_many(query, [param]) +} + +fn (db DB) handle_error_or_result(res voidptr, elabel string) ?[]Row { + e := unsafe { C.PQerrorMessage(db.conn).vstring() } + if e != '' { + C.PQclear(res) + return error('pg $elabel error:\n$e') + } + return res_to_rows(res) +} + +// copy_expert execute COPY commands +// https://www.postgresql.org/docs/9.5/libpq-copy.html +pub fn (db DB) copy_expert(query string, file io.ReaderWriter) ?int { + res := C.PQexec(db.conn, query.str) + status := C.PQresultStatus(res) + + defer { + C.PQclear(res) + } + + e := unsafe { C.PQerrorMessage(db.conn).vstring() } + if e != '' { + return error('pg copy error:\n$e') + } + + if status == C.PGRES_COPY_IN { + mut buf := []byte{len: 4 * 1024} + for { + n := file.read(mut buf) or { + msg := 'pg copy error: Failed to read from input' + C.PQputCopyEnd(db.conn, msg.str) + return err + } + if n <= 0 { + break + } + + code := C.PQputCopyData(db.conn, buf.data, n) + if code == -1 { + return error('pg copy error: Failed to send data, code=$code') + } + } + + code := C.PQputCopyEnd(db.conn, 0) + + if code != 1 { + return error('pg copy error: Failed to finish copy command, code: $code') + } + } else if status == C.PGRES_COPY_OUT { + for { + address := &byte(0) + n_bytes := C.PQgetCopyData(db.conn, &address, 0) + if n_bytes > 0 { + mut local_buf := []byte{len: n_bytes} + unsafe { C.memcpy(&byte(local_buf.data), address, n_bytes) } + file.write(local_buf) or { + C.PQfreemem(address) + return err + } + } else if n_bytes == -1 { + break + } else if n_bytes == -2 { + // consult PQerrorMessage for the reason + return error('pg copy error: read error') + } + if address != 0 { + C.PQfreemem(address) + } + } + } + + return 0 +} |