union StreamSource [src]

Alias for std.io.stream_source.StreamSource

Provides io.Reader, io.Writer, and io.SeekableStream for in-memory buffers as well as files. For memory sources, if the supplied byte buffer is const, then io.Writer is not available. The error set of the stream functions is the error set of the corresponding file functions.

Fields

buffer: io.FixedBufferStream([]u8)The stream access is redirected to this buffer.

const_buffer: io.FixedBufferStream([]const u8)The stream access is redirected to this buffer. Writing to the source will always yield error.AccessDenied.

file: if (has_file) std.fs.File else voidThe stream access is redirected to this file. On freestanding, this must never be initialized!

Members

getEndPos (Function)
getPos (Function)
GetSeekPosError (Error Set)
read (Function)
reader (Function)
Reader (Type)
ReadError (Error Set)
seekableStream (Function)
SeekableStream (Type)
seekBy (Function)
SeekError (Error Set)
seekTo (Function)
write (Function)
WriteError (Error Set)
writer (Function)
Writer (Type)

Source

  pub const StreamSource = union(enum) {
    // TODO: expose UEFI files to std.os in a way that allows this to be true
    const has_file = (builtin.os.tag != .freestanding and builtin.os.tag != .uefi);

    /// The stream access is redirected to this buffer.
    buffer: io.FixedBufferStream([]u8),

    /// The stream access is redirected to this buffer.
    /// Writing to the source will always yield `error.AccessDenied`.
    const_buffer: io.FixedBufferStream([]const u8),

    /// The stream access is redirected to this file.
    /// On freestanding, this must never be initialized!
    file: if (has_file) std.fs.File else void,

    pub const ReadError = io.FixedBufferStream([]u8).ReadError || (if (has_file) std.fs.File.ReadError else error{});
    pub const WriteError = error{AccessDenied} || io.FixedBufferStream([]u8).WriteError || (if (has_file) std.fs.File.WriteError else error{});
    pub const SeekError = io.FixedBufferStream([]u8).SeekError || (if (has_file) std.fs.File.SeekError else error{});
    pub const GetSeekPosError = io.FixedBufferStream([]u8).GetSeekPosError || (if (has_file) std.fs.File.GetSeekPosError else error{});

    pub const Reader = io.Reader(*StreamSource, ReadError, read);
    pub const Writer = io.Writer(*StreamSource, WriteError, write);
    pub const SeekableStream = io.SeekableStream(
        *StreamSource,
        SeekError,
        GetSeekPosError,
        seekTo,
        seekBy,
        getPos,
        getEndPos,
    );

    pub fn read(self: *StreamSource, dest: []u8) ReadError!usize {
        switch (self.*) {
            .buffer => |*x| return x.read(dest),
            .const_buffer => |*x| return x.read(dest),
            .file => |x| if (!has_file) unreachable else return x.read(dest),
        }
    }

    pub fn write(self: *StreamSource, bytes: []const u8) WriteError!usize {
        switch (self.*) {
            .buffer => |*x| return x.write(bytes),
            .const_buffer => return error.AccessDenied,
            .file => |x| if (!has_file) unreachable else return x.write(bytes),
        }
    }

    pub fn seekTo(self: *StreamSource, pos: u64) SeekError!void {
        switch (self.*) {
            .buffer => |*x| return x.seekTo(pos),
            .const_buffer => |*x| return x.seekTo(pos),
            .file => |x| if (!has_file) unreachable else return x.seekTo(pos),
        }
    }

    pub fn seekBy(self: *StreamSource, amt: i64) SeekError!void {
        switch (self.*) {
            .buffer => |*x| return x.seekBy(amt),
            .const_buffer => |*x| return x.seekBy(amt),
            .file => |x| if (!has_file) unreachable else return x.seekBy(amt),
        }
    }

    pub fn getEndPos(self: *StreamSource) GetSeekPosError!u64 {
        switch (self.*) {
            .buffer => |*x| return x.getEndPos(),
            .const_buffer => |*x| return x.getEndPos(),
            .file => |x| if (!has_file) unreachable else return x.getEndPos(),
        }
    }

    pub fn getPos(self: *StreamSource) GetSeekPosError!u64 {
        switch (self.*) {
            .buffer => |*x| return x.getPos(),
            .const_buffer => |*x| return x.getPos(),
            .file => |x| if (!has_file) unreachable else return x.getPos(),
        }
    }

    pub fn reader(self: *StreamSource) Reader {
        return .{ .context = self };
    }

    pub fn writer(self: *StreamSource) Writer {
        return .{ .context = self };
    }

    pub fn seekableStream(self: *StreamSource) SeekableStream {
        return .{ .context = self };
    }
}  