Function readToEndAllocOptions [src]

Reads all the bytes from the current position to the end of the file. On success, caller owns returned buffer. If the file is larger than max_bytes, returns error.FileTooBig. If size_hint is specified the initial buffer size is calculated using that value, otherwise an arbitrary value is used instead. Allows specifying alignment and a sentinel value.

Prototype

 pub fn readToEndAllocOptions( self: File, allocator: Allocator, max_bytes: usize, size_hint: ?usize, comptime alignment: u29, comptime optional_sentinel: ?u8, ) !(if (optional_sentinel) |s| [:s]align(alignment) u8 else []align(alignment) u8)

Parameters

self: Fileallocator: Allocatormax_bytes: usizesize_hint: ?usizealignment: u29optional_sentinel: ?u8

Source

  pub fn readToEndAllocOptions(
    self: File,
    allocator: Allocator,
    max_bytes: usize,
    size_hint: ?usize,
    comptime alignment: u29,
    comptime optional_sentinel: ?u8,
) !(if (optional_sentinel) |s| [:s]align(alignment) u8 else []align(alignment) u8) {
    // If no size hint is provided fall back to the size=0 code path
    const size = size_hint orelse 0;

    // The file size returned by stat is used as hint to set the buffer
    // size. If the reported size is zero, as it happens on Linux for files
    // in /proc, a small buffer is allocated instead.
    const initial_cap = @min((if (size > 0) size else 1024), max_bytes) + @intFromBool(optional_sentinel != null);
    var array_list = try std.ArrayListAligned(u8, alignment).initCapacity(allocator, initial_cap);
    defer array_list.deinit();

    self.reader().readAllArrayListAligned(alignment, &array_list, max_bytes) catch |err| switch (err) {
        error.StreamTooLong => return error.FileTooBig,
        else => |e| return e,
    };

    if (optional_sentinel) |sentinel| {
        return try array_list.toOwnedSliceSentinel(sentinel);
    } else {
        return try array_list.toOwnedSlice();
    }
}  