Files
browser/src/url/query.zig
2024-05-13 20:51:36 +02:00

284 lines
8.2 KiB
Zig

// Copyright (C) 2023-2024 Lightpanda (Selecy SAS)
//
// Francis Bouvier <francis@lightpanda.io>
// Pierre Tachoire <pierre@lightpanda.io>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
const std = @import("std");
const Reader = @import("../str/parser.zig").Reader;
// Values is a map with string key of string values.
pub const Values = struct {
alloc: std.mem.Allocator,
map: std.StringArrayHashMapUnmanaged(List),
const List = std.ArrayListUnmanaged([]const u8);
pub fn init(alloc: std.mem.Allocator) Values {
return .{
.alloc = alloc,
.map = .{},
};
}
pub fn deinit(self: *Values) void {
var it = self.map.iterator();
while (it.next()) |entry| {
for (entry.value_ptr.items) |v| self.alloc.free(v);
entry.value_ptr.deinit(self.alloc);
self.alloc.free(entry.key_ptr.*);
}
self.map.deinit(self.alloc);
}
// add the key value couple to the values.
// the key and the value are duplicated.
pub fn append(self: *Values, k: []const u8, v: []const u8) !void {
const vv = try self.alloc.dupe(u8, v);
if (self.map.getPtr(k)) |list| {
return try list.append(self.alloc, vv);
}
const kk = try self.alloc.dupe(u8, k);
var list = List{};
try list.append(self.alloc, vv);
try self.map.put(self.alloc, kk, list);
}
// append by taking the ownership of the key and the value
fn appendOwned(self: *Values, k: []const u8, v: []const u8) !void {
if (self.map.getPtr(k)) |list| {
return try list.append(self.alloc, v);
}
var list = List{};
try list.append(self.alloc, v);
try self.map.put(self.alloc, k, list);
}
pub fn get(self: *Values, k: []const u8) [][]const u8 {
if (self.map.get(k)) |list| {
return list.items;
}
return &[_][]const u8{};
}
pub fn first(self: *Values, k: []const u8) []const u8 {
if (self.map.getPtr(k)) |list| {
if (list.items.len == 0) return "";
return list.items[0];
}
return "";
}
pub fn delete(self: *Values, k: []const u8) void {
if (self.map.getPtr(k)) |list| {
list.deinit(self.alloc);
_ = self.map.fetchSwapRemove(k);
}
}
pub fn deleteValue(self: *Values, k: []const u8, v: []const u8) void {
const list = self.map.getPtr(k) orelse return;
for (list.items, 0..) |vv, i| {
if (std.mem.eql(u8, v, vv)) {
_ = list.swapRemove(i);
return;
}
}
}
pub fn count(self: *Values) usize {
return self.map.count();
}
// the caller owned the returned string.
pub fn encode(self: *Values, writer: anytype) !void {
var i: usize = 0;
var it = self.map.iterator();
while (it.next()) |entry| {
defer i += 1;
if (i > 0) try writer.writeByte('&');
if (entry.value_ptr.items.len == 0) {
try escape(writer, entry.key_ptr.*);
continue;
}
const start = i;
for (entry.value_ptr.items) |v| {
defer i += 1;
if (start < i) try writer.writeByte('&');
try escape(writer, entry.key_ptr.*);
if (v.len > 0) try writer.writeByte('=');
try escape(writer, v);
}
}
}
};
fn unhex(c: u8) u8 {
if ('0' <= c and c <= '9') return c - '0';
if ('a' <= c and c <= 'f') return c - 'a' + 10;
if ('A' <= c and c <= 'F') return c - 'A' + 10;
return 0;
}
// unescape decodes a percent encoded string.
// The caller owned the returned string.
pub fn unescape(alloc: std.mem.Allocator, s: []const u8) ![]const u8 {
var buf: std.ArrayListUnmanaged(u8) = .{};
defer buf.deinit(alloc);
var i: usize = 0;
while (i < s.len) {
defer i += 1;
switch (s[i]) {
'%' => {
if (i + 2 > s.len) return error.EscapeError;
if (!std.ascii.isHex(s[i + 1])) return error.EscapeError;
if (!std.ascii.isHex(s[i + 2])) return error.EscapeError;
try buf.append(alloc, unhex(s[i + 1]) << 4 | unhex(s[i + 2]));
i += 2;
},
'+' => try buf.append(alloc, ' '), // TODO should we decode or keep as it?
else => try buf.append(alloc, s[i]),
}
}
return try buf.toOwnedSlice(alloc);
}
test "unescape" {
var v: []const u8 = undefined;
const alloc = std.testing.allocator;
v = try unescape(alloc, "%7E");
try std.testing.expect(std.mem.eql(u8, "~", v));
alloc.free(v);
}
pub fn escape(writer: anytype, raw: []const u8) !void {
var start: usize = 0;
for (raw, 0..) |char, index| {
if ('a' <= char and char <= 'z' or 'A' <= char and char <= 'Z' or '0' <= char and char <= '9') {
continue;
}
try writer.print("{s}%{X:0>2}", .{ raw[start..index], char });
start = index + 1;
}
try writer.writeAll(raw[start..]);
}
// Parse the given query.
pub fn parseQuery(alloc: std.mem.Allocator, s: []const u8) !Values {
var values = Values.init(alloc);
errdefer values.deinit();
const ln = s.len;
if (ln == 0) return values;
var r = Reader{ .s = s };
while (true) {
const param = r.until('&');
if (param.len == 0) break;
var rr = Reader{ .s = param };
const k = rr.until('=');
if (k.len == 0) continue;
_ = rr.skip();
const v = rr.tail();
// decode k and v
const kk = try unescape(alloc, k);
const vv = try unescape(alloc, v);
try values.appendOwned(kk, vv);
if (!r.skip()) break;
}
return values;
}
test "parse empty query" {
var values = try parseQuery(std.testing.allocator, "");
defer values.deinit();
try std.testing.expect(values.count() == 0);
}
test "parse empty query &" {
var values = try parseQuery(std.testing.allocator, "&");
defer values.deinit();
try std.testing.expect(values.count() == 0);
}
test "parse query" {
var values = try parseQuery(std.testing.allocator, "a=b&b=c");
defer values.deinit();
try std.testing.expect(values.count() == 2);
try std.testing.expect(values.get("a").len == 1);
try std.testing.expect(std.mem.eql(u8, values.get("a")[0], "b"));
try std.testing.expect(std.mem.eql(u8, values.first("a"), "b"));
try std.testing.expect(values.get("b").len == 1);
try std.testing.expect(std.mem.eql(u8, values.get("b")[0], "c"));
try std.testing.expect(std.mem.eql(u8, values.first("b"), "c"));
}
test "parse query no value" {
var values = try parseQuery(std.testing.allocator, "a");
defer values.deinit();
try std.testing.expect(values.count() == 1);
try std.testing.expect(std.mem.eql(u8, values.first("a"), ""));
}
test "parse query dup" {
var values = try parseQuery(std.testing.allocator, "a=b&a=c");
defer values.deinit();
try std.testing.expect(values.count() == 1);
try std.testing.expect(std.mem.eql(u8, values.first("a"), "b"));
try std.testing.expect(values.get("a").len == 2);
}
test "encode query" {
var values = try parseQuery(std.testing.allocator, "a=b&b=c");
defer values.deinit();
try values.append("a", "~");
var buf: std.ArrayListUnmanaged(u8) = .{};
defer buf.deinit(std.testing.allocator);
try values.encode(buf.writer(std.testing.allocator));
try std.testing.expect(std.mem.eql(u8, buf.items, "a=b&a=%7E&b=c"));
}