Commit e831313b10

@@ -1,379 +0,0 @@
-const std = @import("std");
-const io = std.io;
-const assert = std.debug.assert;
-const testing = std.testing;
-
-/// BufferedTee provides reader interface to the consumer. Data read by consumer
-/// is also written to the output. Output is hold lookahead_size bytes behind
-/// consumer. Allowing consumer to put back some bytes to be read again. On flush
-/// all consumed bytes are flushed to the output.
-///
-///       input   ->   tee   ->   consumer
-///                     |
-///                  output
-///
-/// input - underlying unbuffered reader
-/// output - writer, receives data read by consumer
-/// consumer - uses provided reader interface
-///
-/// If lookahead_size is zero output always has same bytes as consumer.
-///
-pub fn BufferedTee(
-    comptime buffer_size: usize, // internal buffer size in bytes
-    comptime lookahead_size: usize, // lookahead, number of bytes to hold output behind consumer
-    comptime InputReaderType: type,
-    comptime OutputWriterType: type,
-) type {
-    comptime assert(buffer_size > lookahead_size);
-
-    return struct {
-        input: InputReaderType,
-        output: OutputWriterType,
-
-        buf: [buffer_size]u8 = undefined, // internal buffer
-        tail: usize = 0, // buffer is filled up to this position with bytes from input
-        rp: usize = 0, // reader pointer; consumer has read up to this position
-        wp: usize = 0, // writer pointer; data is sent to the output up to this position
-
-        pub const Error = InputReaderType.Error || OutputWriterType.Error;
-        pub const Reader = io.Reader(*Self, Error, read);
-
-        const Self = @This();
-
-        pub fn read(self: *Self, dest: []u8) Error!usize {
-            var dest_index: usize = 0;
-
-            while (dest_index < dest.len) {
-                const written = @min(dest.len - dest_index, self.tail - self.rp);
-                if (written == 0) {
-                    try self.preserveLookahead();
-                    // fill upper part of the buf
-                    const n = try self.input.read(self.buf[self.tail..]);
-                    if (n == 0) {
-                        // reading from the unbuffered stream returned nothing
-                        // so we have nothing left to read.
-                        return dest_index;
-                    }
-                    self.tail += n;
-                } else {
-                    @memcpy(dest[dest_index..][0..written], self.buf[self.rp..][0..written]);
-                    self.rp += written;
-                    dest_index += written;
-                    try self.flush_(lookahead_size);
-                }
-            }
-            return dest.len;
-        }
-
-        /// Move lookahead_size bytes to the buffer start.
-        fn preserveLookahead(self: *Self) !void {
-            assert(self.tail == self.rp);
-            if (lookahead_size == 0) {
-                // Flush is called on each read so wp must follow rp when lookahead_size == 0.
-                assert(self.wp == self.rp);
-                // Nothing to preserve rewind pointer to the buffer start
-                self.rp = 0;
-                self.wp = 0;
-                self.tail = 0;
-                return;
-            }
-            if (self.tail <= lookahead_size) {
-                // There is still palce in the buffer, append to buffer from tail position.
-                return;
-            }
-            try self.flush_(lookahead_size);
-            const head = self.tail - lookahead_size;
-            // Preserve head..tail at the start of the buffer.
-            std.mem.copyForwards(u8, self.buf[0..lookahead_size], self.buf[head..self.tail]);
-            self.wp -= head;
-            assert(self.wp <= lookahead_size);
-            self.rp = lookahead_size;
-            self.tail = lookahead_size;
-        }
-
-        /// Flush to the output all but lookahead size bytes.
-        fn flush_(self: *Self, lookahead: usize) !void {
-            if (self.rp <= self.wp + lookahead) return;
-            const new_wp = self.rp - lookahead;
-            try self.output.writeAll(self.buf[self.wp..new_wp]);
-            self.wp = new_wp;
-        }
-
-        /// Flush to the output all consumed bytes.
-        pub fn flush(self: *Self) !void {
-            try self.flush_(0);
-        }
-
-        /// Put back some bytes to be consumed again. Usefull when we overshoot
-        /// reading and want to return that overshoot bytes. Can return maximum
-        /// of lookahead_size number of bytes.
-        pub fn putBack(self: *Self, n: usize) void {
-            assert(n <= lookahead_size and n <= self.rp);
-            self.rp -= n;
-        }
-
-        pub fn reader(self: *Self) Reader {
-            return .{ .context = self };
-        }
-    };
-}
-
-pub fn bufferedTee(
-    comptime buffer_size: usize,
-    comptime lookahead_size: usize,
-    input: anytype,
-    output: anytype,
-) BufferedTee(
-    buffer_size,
-    lookahead_size,
-    @TypeOf(input),
-    @TypeOf(output),
-) {
-    return .{ .input = input, .output = output };
-}
-
-// Running test from std.io.BufferedReader on BufferedTee
-// It should act as BufferedReader for consumer.
-
-fn BufferedReader(comptime buffer_size: usize, comptime ReaderType: type) type {
-    return BufferedTee(buffer_size, 0, ReaderType, @TypeOf(io.null_writer));
-}
-
-fn bufferedReader(reader: anytype) BufferedReader(4096, @TypeOf(reader)) {
-    return .{
-        .input = reader,
-        .output = io.null_writer,
-    };
-}
-
-test "OneByte" {
-    const OneByteReadReader = struct {
-        str: []const u8,
-        curr: usize,
-
-        const Error = error{NoError};
-        const Self = @This();
-        const Reader = io.Reader(*Self, Error, read);
-
-        fn init(str: []const u8) Self {
-            return Self{
-                .str = str,
-                .curr = 0,
-            };
-        }
-
-        fn read(self: *Self, dest: []u8) Error!usize {
-            if (self.str.len <= self.curr or dest.len == 0)
-                return 0;
-
-            dest[0] = self.str[self.curr];
-            self.curr += 1;
-            return 1;
-        }
-
-        fn reader(self: *Self) Reader {
-            return .{ .context = self };
-        }
-    };
-
-    const str = "This is a test";
-    var one_byte_stream = OneByteReadReader.init(str);
-    var buf_reader = bufferedReader(one_byte_stream.reader());
-    const stream = buf_reader.reader();
-
-    const res = try stream.readAllAlloc(testing.allocator, str.len + 1);
-    defer testing.allocator.free(res);
-    try testing.expectEqualSlices(u8, str, res);
-}
-
-test "Block" {
-    const BlockReader = struct {
-        block: []const u8,
-        reads_allowed: usize,
-        curr_read: usize,
-
-        const Error = error{NoError};
-        const Self = @This();
-        const Reader = io.Reader(*Self, Error, read);
-
-        fn init(block: []const u8, reads_allowed: usize) Self {
-            return Self{
-                .block = block,
-                .reads_allowed = reads_allowed,
-                .curr_read = 0,
-            };
-        }
-
-        fn read(self: *Self, dest: []u8) Error!usize {
-            if (self.curr_read >= self.reads_allowed) return 0;
-            @memcpy(dest[0..self.block.len], self.block);
-
-            self.curr_read += 1;
-            return self.block.len;
-        }
-
-        fn reader(self: *Self) Reader {
-            return .{ .context = self };
-        }
-    };
-
-    const block = "0123";
-
-    // len out == block
-    {
-        var test_buf_reader: BufferedReader(4, BlockReader) = .{
-            .input = BlockReader.init(block, 2),
-            .output = io.null_writer,
-        };
-        var out_buf: [4]u8 = undefined;
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, block);
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, block);
-        try testing.expectEqual(try test_buf_reader.read(&out_buf), 0);
-    }
-
-    // len out < block
-    {
-        var test_buf_reader: BufferedReader(4, BlockReader) = .{
-            .input = BlockReader.init(block, 2),
-            .output = io.null_writer,
-        };
-        var out_buf: [3]u8 = undefined;
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, "012");
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, "301");
-        const n = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, out_buf[0..n], "23");
-        try testing.expectEqual(try test_buf_reader.read(&out_buf), 0);
-    }
-
-    // len out > block
-    {
-        var test_buf_reader: BufferedReader(4, BlockReader) = .{
-            .input = BlockReader.init(block, 2),
-            .output = io.null_writer,
-        };
-        var out_buf: [5]u8 = undefined;
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, "01230");
-        const n = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, out_buf[0..n], "123");
-        try testing.expectEqual(try test_buf_reader.read(&out_buf), 0);
-    }
-
-    // len out == 0
-    {
-        var test_buf_reader: BufferedReader(4, BlockReader) = .{
-            .input = BlockReader.init(block, 2),
-            .output = io.null_writer,
-        };
-        var out_buf: [0]u8 = undefined;
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, "");
-    }
-
-    // len bufreader buf > block
-    {
-        var test_buf_reader: BufferedReader(5, BlockReader) = .{
-            .input = BlockReader.init(block, 2),
-            .output = io.null_writer,
-        };
-        var out_buf: [4]u8 = undefined;
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, block);
-        _ = try test_buf_reader.read(&out_buf);
-        try testing.expectEqualSlices(u8, &out_buf, block);
-        try testing.expectEqual(try test_buf_reader.read(&out_buf), 0);
-    }
-}
-
-test "with zero lookahead" {
-    // output has same bytes as consumer
-    const data = [_]u8{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } ** 12;
-    var in = io.fixedBufferStream(&data);
-    var out = std.ArrayList(u8).init(testing.allocator);
-    defer out.deinit();
-
-    var bt = bufferedTee(8, 0, in.reader(), out.writer());
-
-    var buf: [16]u8 = undefined;
-    var read_len: usize = 0;
-    for (0..buf.len) |i| {
-        const n = try bt.read(buf[0..i]);
-        try testing.expectEqual(i, n);
-        read_len += i;
-        try testing.expectEqual(read_len, out.items.len);
-    }
-}
-
-test "with lookahead" {
-    // output is lookahead bytes behind consumer
-    inline for (1..8) |lookahead| {
-        const data = [_]u8{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } ** 12;
-        var in = io.fixedBufferStream(&data);
-        var out = std.ArrayList(u8).init(testing.allocator);
-        defer out.deinit();
-
-        var bt = bufferedTee(8, lookahead, in.reader(), out.writer());
-        var buf: [16]u8 = undefined;
-
-        var read_len: usize = 0;
-        for (1..buf.len) |i| {
-            const n = try bt.read(buf[0..i]);
-            try testing.expectEqual(i, n);
-            read_len += i;
-            const out_len = if (read_len < lookahead) 0 else read_len - lookahead;
-            try testing.expectEqual(out_len, out.items.len);
-        }
-        try testing.expectEqual(read_len, out.items.len + lookahead);
-        try bt.flush();
-        try testing.expectEqual(read_len, out.items.len);
-    }
-}
-
-test "internal state" {
-    const data = [_]u8{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } ** 2;
-    var in = io.fixedBufferStream(&data);
-    var out = std.ArrayList(u8).init(testing.allocator);
-    defer out.deinit();
-
-    var bt = bufferedTee(8, 4, in.reader(), out.writer());
-
-    var buf: [16]u8 = undefined;
-    var n = try bt.read(buf[0..3]);
-    try testing.expectEqual(3, n);
-    try testing.expectEqualSlices(u8, data[0..3], buf[0..n]);
-    try testing.expectEqual(8, bt.tail);
-    try testing.expectEqual(3, bt.rp);
-    try testing.expectEqual(0, out.items.len);
-
-    n = try bt.read(buf[0..6]);
-    try testing.expectEqual(6, n);
-    try testing.expectEqualSlices(u8, data[3..9], buf[0..n]);
-    try testing.expectEqual(8, bt.tail);
-    try testing.expectEqual(5, bt.rp);
-    try testing.expectEqualSlices(u8, data[4..12], &bt.buf);
-    try testing.expectEqual(5, out.items.len);
-
-    n = try bt.read(buf[0..9]);
-    try testing.expectEqual(9, n);
-    try testing.expectEqualSlices(u8, data[9..18], buf[0..n]);
-    try testing.expectEqual(8, bt.tail);
-    try testing.expectEqual(6, bt.rp);
-    try testing.expectEqualSlices(u8, data[12..20], &bt.buf);
-    try testing.expectEqual(14, out.items.len);
-
-    try bt.flush();
-    try testing.expectEqual(18, out.items.len);
-
-    bt.putBack(4);
-    n = try bt.read(buf[0..4]);
-    try testing.expectEqual(4, n);
-    try testing.expectEqualSlices(u8, data[14..18], buf[0..n]);
-
-    try testing.expectEqual(18, out.items.len);
-    try bt.flush();
-    try testing.expectEqual(18, out.items.len);
-}

@@ -410,9 +410,6 @@ pub const BufferedAtomicFile = @import("io/buffered_atomic_file.zig").BufferedAt
 
 pub const StreamSource = @import("io/stream_source.zig").StreamSource;
 
-pub const BufferedTee = @import("io/buffered_tee.zig").BufferedTee;
-pub const bufferedTee = @import("io/buffered_tee.zig").bufferedTee;
-
 pub const tty = @import("io/tty.zig");
 
 /// A Writer that doesn't write to anything.
@@ -709,5 +706,4 @@ test {
     _ = @import("io/seekable_stream.zig");
     _ = @import("io/stream_source.zig");
     _ = @import("io/test.zig");
-    _ = @import("io/buffered_tee.zig");
 }