47 lines
1.0 KiB
Rust
47 lines
1.0 KiB
Rust
use solana_program::program_memory::sol_memcpy;
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use std::cmp;
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use std::io::{self, Write};
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#[derive(Debug, Default)]
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pub struct BpfWriter<T> {
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inner: T,
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pos: u64,
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}
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impl<T> BpfWriter<T> {
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pub fn new(inner: T) -> Self {
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Self { inner, pos: 0 }
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}
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}
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impl Write for BpfWriter<&mut [u8]> {
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fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
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if self.pos >= self.inner.len() as u64 {
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return Ok(0);
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}
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let amt = cmp::min(
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self.inner.len().saturating_sub(self.pos as usize),
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buf.len(),
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);
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sol_memcpy(&mut self.inner[(self.pos as usize)..], buf, amt);
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self.pos += amt as u64;
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Ok(amt)
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}
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fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
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if self.write(buf)? == buf.len() {
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Ok(())
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} else {
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Err(io::Error::new(
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io::ErrorKind::WriteZero,
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"failed to write whole buffer",
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))
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}
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}
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fn flush(&mut self) -> io::Result<()> {
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Ok(())
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}
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}
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