46 lines
1002 B
V
46 lines
1002 B
V
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module io
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// Reader represents a stream of data that can be read
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pub interface Reader {
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// read reads up to buf.len bytes and places
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// them into buf.
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// A struct that implements this should return
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// `none` on end of stream (EOF) instead of just returning 0
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read(mut buf []byte) ?int
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}
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// make_reader is a temp that converts a struct to a reader
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// (e.g. for use in struct initialisation)
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pub fn make_reader(r Reader) Reader {
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return r
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}
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const (
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read_all_len = 10 * 1024
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read_all_grow_len = 1024
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)
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// read_all reads all available bytes from a reader
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pub fn read_all(r Reader) ?[]byte {
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mut b := []byte{len:read_all_len}
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mut read := 0
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for {
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new_read := r.read(mut b[read..]) or {
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break
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}
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read += new_read
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if new_read == 0 {
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break
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}
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if b.len == read {
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b.grow(read_all_grow_len)
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}
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}
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return b[..read]
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}
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// RandomReader represents a stream of data that can be read from at a random location
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interface RandomReader {
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read_from(pos int, mut buf []byte) ?int
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}
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