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package io
import "core:mem"
import "core:strconv"
read_ptr :: proc(r: Reader, p: rawptr, byte_size: int) -> (n: int, err: Error) {
return read(r, mem.byte_slice(p, byte_size));
}
write_ptr :: proc(w: Writer, p: rawptr, byte_size: int) -> (n: int, err: Error) {
return write(w, mem.byte_slice(p, byte_size));
}
read_ptr_at :: proc(r: Reader_At, p: rawptr, byte_size: int, offset: i64) -> (n: int, err: Error) {
return read_at(r, mem.byte_slice(p, byte_size), offset);
}
write_ptr_at :: proc(w: Writer_At, p: rawptr, byte_size: int, offset: i64) -> (n: int, err: Error) {
return write_at(w, mem.byte_slice(p, byte_size), offset);
}
write_u64 :: proc(w: Writer, i: u64, base: int = 10) -> (n: int, err: Error) {
buf: [32]byte;
s := strconv.append_bits(buf[:], i, base, false, 64, strconv.digits, nil);
return write_string(w, s);
}
write_i64 :: proc(w: Writer, i: i64, base: int = 10) -> (n: int, err: Error) {
buf: [32]byte;
s := strconv.append_bits(buf[:], u64(i), base, true, 64, strconv.digits, nil);
return write_string(w, s);
}
write_uint :: proc(w: Writer, i: uint, base: int = 10) -> (n: int, err: Error) {
return write_u64(w, u64(i), base);
}
write_int :: proc(w: Writer, i: int, base: int = 10) -> (n: int, err: Error) {
return write_i64(w, i64(i), base);
}
Tee_Reader :: struct {
r: Reader,
w: Writer,
}
@(private)
_tee_reader_vtable := &Stream_VTable{
impl_read = proc(s: Stream, p: []byte) -> (n: int, err: Error) {
t := (^Tee_Reader)(s.stream_data);
n, err = read(t.r, p);
if n > 0 {
if wn, werr := write(t.w, p[:n]); werr != nil {
return wn, werr;
}
}
return;
},
};
// tee_reader_init returns a Reader that writes to 'w' what it reads from 'r'
// All reads from 'r' performed through it are matched with a corresponding write to 'w'
// There is no internal buffering done
// The write must complete before th read completes
// Any error encountered whilst writing is reported as a 'read' error
// tee_reader_init must call io.destroy when done with
tee_reader_init :: proc(t: ^Tee_Reader, r: Reader, w: Writer, allocator := context.allocator) -> Reader {
t.r, t.w = r, w;
return tee_reader_to_reader(t);
}
tee_reader_to_reader :: proc(t: ^Tee_Reader) -> (r: Reader) {
r.stream_data = t;
r.stream_vtable = _tee_reader_vtable;
return;
}
// A Limited_Reader reads from r but limits the amount of data returned to just n bytes.
// Each call to read updates n to reflect the new amount remaining.
// read returns EOF when n <= 0 or when the underlying r returns EOF.
Limited_Reader :: struct {
r: Reader, // underlying reader
n: i64, // max_bytes
}
@(private)
_limited_reader_vtable := &Stream_VTable{
impl_read = proc(s: Stream, p: []byte) -> (n: int, err: Error) {
l := (^Limited_Reader)(s.stream_data);
if l.n <= 0 {
return 0, .EOF;
}
p := p;
if i64(len(p)) > l.n {
p = p[0:l.n];
}
n, err = read(l.r, p);
l.n -= i64(n);
return;
},
};
limited_reader_init :: proc(l: ^Limited_Reader, r: Reader, n: i64) -> Reader {
l.r = r;
l.n = n;
return limited_reader_to_reader(l);
}
limited_reader_to_reader :: proc(l: ^Limited_Reader) -> (r: Reader) {
r.stream_vtable = _limited_reader_vtable;
r.stream_data = l;
return;
}
// Section_Reader implements read, seek, and read_at on a section of an underlying Reader_At
Section_Reader :: struct {
r: Reader_At,
base: i64,
off: i64,
limit: i64,
}
section_reader_init :: proc(s: ^Section_Reader, r: Reader_At, off: i64, n: i64) {
s.r = r;
s.off = off;
s.limit = off + n;
return;
}
section_reader_to_stream :: proc(s: ^Section_Reader) -> (out: Stream) {
out.stream_data = s;
out.stream_vtable = _section_reader_vtable;
return;
}
@(private)
_section_reader_vtable := &Stream_VTable{
impl_read = proc(stream: Stream, p: []byte) -> (n: int, err: Error) {
s := (^Section_Reader)(stream.stream_data);
if s.off >= s.limit {
return 0, .EOF;
}
p := p;
if max := s.limit - s.off; i64(len(p)) > max {
p = p[0:max];
}
n, err = read_at(s.r, p, s.off);
s.off += i64(n);
return;
},
impl_read_at = proc(stream: Stream, p: []byte, off: i64) -> (n: int, err: Error) {
s := (^Section_Reader)(stream.stream_data);
p, off := p, off;
if off < 0 || off >= s.limit - s.base {
return 0, .EOF;
}
off += s.base;
if max := s.limit - off; i64(len(p)) > max {
p = p[0:max];
n, err = read_at(s.r, p, off);
if err == nil {
err = .EOF;
}
return;
}
return read_at(s.r, p, off);
},
impl_seek = proc(stream: Stream, offset: i64, whence: Seek_From) -> (n: i64, err: Error) {
s := (^Section_Reader)(stream.stream_data);
offset := offset;
switch whence {
case:
return 0, .Invalid_Whence;
case .Start:
offset += s.base;
case .Current:
offset += s.off;
case .End:
offset += s.limit;
}
if offset < s.base {
return 0, .Invalid_Offset;
}
s.off = offset;
n = offset - s.base;
return;
},
impl_size = proc(stream: Stream) -> i64 {
s := (^Section_Reader)(stream.stream_data);
return s.limit - s.base;
},
};
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