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extern crate libc;
use libc::{c_int, size_t};
pub fn compress(src: &[u8], dst: &mut [u8]) -> Result<usize, String> {
unsafe {
let mut dst_len = snappy_max_compressed_length(src.len());
if dst.len() < dst_len {
return Err(format!(
"destination buffer too small ({} < {})",
dst.len(), dst_len));
}
snappy_compress(
src.as_ptr(),
src.len(),
dst.as_mut_ptr(),
&mut dst_len);
Ok(dst_len)
}
}
pub fn decompress(src: &[u8], dst: &mut [u8]) -> Result<usize, String> {
unsafe {
let mut dst_len = 0;
snappy_uncompressed_length(
src.as_ptr(), src.len() as size_t, &mut dst_len);
if dst.len() < dst_len {
return Err(format!(
"destination buffer too small ({} < {})", dst.len(), dst_len));
}
let r = snappy_uncompress(
src.as_ptr(),
src.len(),
dst.as_mut_ptr(),
&mut dst_len);
if r == 0 {
Ok(dst_len)
} else {
Err("snappy: invalid input".to_owned())
}
}
}
extern {
fn snappy_compress(
input: *const u8,
input_len: size_t,
compressed: *mut u8,
compressed_len: *mut size_t,
) -> c_int;
fn snappy_uncompress(
compressed: *const u8,
compressed_len: size_t,
uncompressed: *mut u8,
uncompressed_len: *mut size_t,
) -> c_int;
fn snappy_max_compressed_length(input_len: size_t) -> size_t;
fn snappy_uncompressed_length(
compressed: *const u8,
compressed_len: size_t,
result: *mut size_t,
) -> c_int;
}