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| 1 | const std = @import("std"); |
| 2 | const builtin = @import("builtin"); |
| 3 | const extras = @import("extras"); |
| 4 | const nio = @import("./nio.zig"); |
| 5 | const standard_alphabet_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 6 | const url_safe_alphabet_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_".*; |
| 7 | |
| 8 | pub fn Base64Reader(comptime ReaderType: type) type { |
| 9 | return struct { |
| 10 | source_reader: ReaderType, |
| 11 | alphabet: *const [64]u8, |
| 12 | bits: std.bit_set.IntegerBitSet(bit_max), |
| 13 | jdx: u8, |
| 14 | |
| 15 | const Self = @This(); |
| 16 | const bit_max = std.math.log2(64); // 6 |
| 17 | |
| 18 | pub fn init(source_reader: ReaderType) Self { |
| 19 | return .{ |
| 20 | .source_reader = source_reader, |
| 21 | .alphabet = standard_alphabet_chars, |
| 22 | .bits = .empty, |
| 23 | .jdx = bit_max, |
| 24 | }; |
| 25 | } |
| 26 | |
| 27 | pub fn from(source_reader: anytype) Base64Reader(@TypeOf(source_reader)) { |
| 28 | return .init(source_reader); |
| 29 | } |
| 30 | |
| 31 | const R = nio.Readable(@This(), ._var); |
| 32 | pub const readAll = R.readAll; |
| 33 | pub const readAtLeast = R.readAtLeast; |
| 34 | pub const readNoEof = R.readNoEof; |
| 35 | pub const readAllAlloc = R.readAllAlloc; |
| 36 | pub const readArray = R.readArray; |
| 37 | pub const readByte = R.readByte; |
| 38 | pub const readUntilDelimiterArrayList = R.readUntilDelimiterArrayList; |
| 39 | pub const readUntilDelimiterAlloc = R.readUntilDelimiterAlloc; |
| 40 | pub const readUntilDelimiterOrEofAlloc = R.readUntilDelimiterOrEofAlloc; |
| 41 | pub const readUntilDelimitersBuf = R.readUntilDelimitersBuf; |
| 42 | pub const readUntilDelimitersArrayList = R.readUntilDelimitersArrayList; |
| 43 | pub const readAlloc = R.readAlloc; |
| 44 | pub const readInt = R.readInt; |
| 45 | pub const readUntilDelimitersAlloc = R.readUntilDelimitersAlloc; |
| 46 | pub const readUntilDelimiter = R.readUntilDelimiter; |
| 47 | pub const readUntilDelimiterOrEof = R.readUntilDelimiterOrEof; |
| 48 | pub const readExpected = R.readExpected; |
| 49 | pub const readType = R.readType; |
| 50 | pub const skipBytes = R.skipBytes; |
| 51 | pub const skipUntilDelimiterOrEof = R.skipUntilDelimiterOrEof; |
| 52 | pub const pipeTo = R.pipeTo; |
| 53 | |
| 54 | pub const ReadError = extras.Pointee(ReaderType).ReadError || error{InvalidCharacter}; |
| 55 | pub fn read(self: *Self, dest: []u8) ReadError!usize { |
| 56 | var i: usize = 0; |
| 57 | while (i < dest.len) { |
| 58 | dest[i] = self.nextInt(u8) catch |err| switch (err) { |
| 59 | error.EndOfStream => break, |
| 60 | else => |e| return e, |
| 61 | }; |
| 62 | i += 1; |
| 63 | } |
| 64 | return i; |
| 65 | } |
| 66 | |
| 67 | pub fn anyReadable(self: *Self) nio.AnyReadable { |
| 68 | const S = struct { |
| 69 | fn read(s: *allowzero anyopaque, buffer: []u8) anyerror!usize { |
| 70 | const br: *Self = @ptrCast(@alignCast(s)); |
| 71 | return br.read(buffer); |
| 72 | } |
| 73 | }; |
| 74 | return .{ |
| 75 | .vtable = &.{ .read = S.read }, |
| 76 | .state = @ptrCast(self), |
| 77 | }; |
| 78 | } |
| 79 | |
| 80 | pub fn next(self: *Self) !u1 { |
| 81 | if (self.jdx == bit_max) { |
| 82 | const c = try self.source_reader.readByte(); |
| 83 | self.bits.mask = @intCast(std.mem.findScalar(u8, self.alphabet, c) orelse if (c == '=') 0 else return error.InvalidCharacter); |
| 84 | self.jdx = 0; |
| 85 | return self.next(); |
| 86 | } |
| 87 | defer self.jdx += 1; |
| 88 | return @intFromBool(self.bits.isSet(bit_max - 1 - self.jdx)); |
| 89 | } |
| 90 | |
| 91 | pub fn nextInt(self: *Self, T: type) !T { |
| 92 | const info = @typeInfo(T).int; |
| 93 | var result: T = 0; |
| 94 | for (0..info.bits) |_| { |
| 95 | result <<= 1; |
| 96 | const val = try self.next(); |
| 97 | result += val; |
| 98 | } |
| 99 | return result; |
| 100 | } |
| 101 | }; |
| 102 | } |
Meghan Denny <hello@nektro.net> 2026-07-10 19:58:39 -07:00
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