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authorMartin Ashby <martin@ashbysoft.com>2023-08-22 10:49:17 +0100
committerMartin Ashby <martin@ashbysoft.com>2023-08-22 10:49:17 +0100
commit7ed589a06539fcc91ab779a1e6de0a995f8238b5 (patch)
treef23bd017d43af4714280aea2d152379370393214 /zig-comments/src/pq.zig
parent8f7f272d68b4197f17d1e76c97546017b8ebea90 (diff)
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Replace comments with zig version
Diffstat (limited to 'zig-comments/src/pq.zig')
-rw-r--r--zig-comments/src/pq.zig151
1 files changed, 0 insertions, 151 deletions
diff --git a/zig-comments/src/pq.zig b/zig-comments/src/pq.zig
deleted file mode 100644
index a4fc382..0000000
--- a/zig-comments/src/pq.zig
+++ /dev/null
@@ -1,151 +0,0 @@
-const std = @import("std");
-const pq = @cImport(
- @cInclude("libpq-fe.h"),
-);
-
-pub const PqError = error{PqError};
-
-// libpq wrapper
-// later, this could be a pure-zig client implementation
-pub const Db = struct {
- c_conn: *pq.PGconn,
- pub fn init(connect_url: [:0]const u8) !Db {
- if (pq.PQisthreadsafe() == 0) {
- std.log.err("PQisthreadsafe returned 0, can't use libpq in this program", .{});
- return PqError.PqError;
- }
- var maybe_conn: ?*pq.PGconn = pq.PQconnectdb(connect_url);
- if (maybe_conn == null) {
- std.log.err("PQconnectdb returned null", .{});
- return PqError.PqError;
- }
- if (pq.PQstatus(maybe_conn) == pq.CONNECTION_BAD) {
- std.log.err("PQstatus returned CONNECTION_BAD: {s}", .{pq.PQerrorMessage(maybe_conn)});
-
- return PqError.PqError;
- } else if (pq.PQstatus(maybe_conn) != pq.CONNECTION_OK) {
- std.log.err("PQstatus returned unknown status {}: {s}", .{ pq.PQstatus(maybe_conn), pq.PQerrorMessage(maybe_conn) });
- return PqError.PqError;
- }
- return Db{
- .c_conn = maybe_conn.?,
- };
- }
-
- pub fn deinit(self: Db) void {
- pq.PQfinish(self.c_conn);
- }
-
- pub fn exec(self: Db, query: [:0]const u8) !void {
- var res: ?*pq.PGresult = pq.PQexec(self.c_conn, query);
- defer pq.PQclear(res);
- var est: pq.ExecStatusType = pq.PQresultStatus(res);
- if (est != pq.PGRES_COMMAND_OK) {
- std.log.err("PQexec error code {} message {s}", .{ est, pq.PQerrorMessage(self.c_conn) });
- return PqError.PqError;
- }
- }
-
- pub fn prepare_statement(self: Db, allocator: std.mem.Allocator, query: [:0]const u8) PqError!Stmt {
- return Stmt{
- .db = self,
- .aa = std.heap.ArenaAllocator.init(allocator),
- .query = query,
- };
- }
-};
-
-pub const Stmt = struct {
- const MAX_PARAMS = 128;
- db: Db,
- query: [:0]const u8,
- aa: std.heap.ArenaAllocator,
-
- n_params: usize = 0,
- param_values: [MAX_PARAMS][*c]const u8 = undefined,
- did_exec: bool = false,
- c_res: ?*pq.PGresult = null,
- res_index: c_int = -1,
- n_tuples: c_int = -1,
- n_fields: c_int = -1,
-
- pub fn deinit(self: *Stmt) void {
- self.aa.deinit();
- if (self.c_res != null) {
- pq.PQclear(self.c_res);
- }
- }
-
- pub fn step(self: *Stmt) !bool {
- if (!self.did_exec) {
- self.did_exec = true;
- self.c_res = pq.PQexecParams(self.db.c_conn, self.query, @as(c_int, @intCast(self.n_params)), null, &self.param_values, null, null, 0);
- const rs = pq.PQresultStatus(self.c_res);
- if (rs != pq.PGRES_TUPLES_OK and rs != pq.PGRES_SINGLE_TUPLE and rs != pq.PGRES_COMMAND_OK) {
- std.log.err("PQresultStatus {} error: {s}", .{ rs, pq.PQerrorMessage(self.db.c_conn) });
- return PqError.PqError;
- }
- self.n_tuples = pq.PQntuples(self.c_res);
- self.n_fields = pq.PQnfields(self.c_res);
- }
- self.res_index = self.res_index + 1;
- return self.res_index < self.n_tuples;
- }
-
- pub fn read_column(self: Stmt, idx: c_int, comptime T: type) !T {
- const value_c: [*c]u8 = pq.PQgetvalue(self.c_res, self.res_index, idx);
- const value: []const u8 = std.mem.sliceTo(value_c, 0);
- return switch (@typeInfo(T)) {
- .Int => std.fmt.parseInt(T, value, 10),
- .Pointer => |ptrinfo| blk: {
- if (ptrinfo.child != u8) {
- @compileError("pointer type []const u8 only is supported in read_column");
- }
- if (ptrinfo.size != .Slice) {
- @compileError("pointer type []const u8 only is supported in read_column");
- }
- break :blk value;
- },
- else => @compileError("unhandled type " ++ @tagName(@typeInfo(T)) ++ " in read_column"),
- };
- }
-
- pub fn read_columnN(self: Stmt, name: [:0]const u8, comptime T: type) !T {
- const idx = pq.PQfnumber(self.c_res, name.ptr);
- if (idx == -1) {
- std.log.err("read_columnN ColumnNotFound [{s}]", .{name});
- return error.ColumnNotFound;
- }
- return read_column(self, idx, T);
- }
-
- pub fn bind(self: *Stmt, idx: usize, t: anytype) !void {
- const T = @TypeOf(t);
- const value: [:0]const u8 = switch (@typeInfo(T)) {
- .Pointer => try std.fmt.allocPrintZ(self.aa.allocator(), "{s}", .{t}),
- .Int => try std.fmt.allocPrintZ(self.aa.allocator(), "{d}", .{t}),
- else => @compileError("unhandled type " ++ @tagName(@typeInfo(T) ++ " in bind")),
- };
- self.param_values[idx] = value.ptr;
- self.n_params = @max(self.n_params, idx + 1);
- }
-
- pub fn read_struct(self: Stmt, comptime T: type) !T {
- const ti = @typeInfo(T);
- var t: T = undefined;
- inline for (ti.Struct.fields) |field| {
- const name: [:0]const u8 = &addZ(field.name.len, field.name[0..].*);
- const val = try self.read_columnN(name, field.type);
- @field(t, field.name) = val;
- }
- return t;
- }
-};
-
-// https://github.com/ziglang/zig/issues/16116
-pub fn addZ(comptime length: usize, value: [length]u8) [length:0]u8 {
- var terminated_value: [length:0]u8 = undefined;
- terminated_value[length] = 0;
- @memcpy(&terminated_value, &value);
- return terminated_value;
-}