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errors: make exit codes class variables instead...
errors: make exit codes class variables instead Kyle pointed out to me that we can simply make the exit codes class variables. Python provides some magic for making them accessible as instance variables. This also makes it easier to let subclasses of existing errors override the exit codes by letting them simply define their own values as class variables. That means that there's no need to pass them into the superclass's constructor arguments, so the superclass doesn't need to expose the them as arguments. (Making a subclass set a different exit code for a subclass of `StorageError` was actually the goal with my recent series.) Differential Revision: https://phab.mercurial-scm.org/D10758

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path_encode.rs
653 lines | 20.8 KiB | application/rls-services+xml | RustLexer
use crypto::digest::Digest;
use crypto::sha1::Sha1;
#[derive(PartialEq, Debug)]
#[allow(non_camel_case_types)]
enum path_state {
START, /* first byte of a path component */
A, /* "AUX" */
AU,
THIRD, /* third of a 3-byte sequence, e.g. "AUX", "NUL" */
C, /* "CON" or "COMn" */
CO,
COMLPT, /* "COM" or "LPT" */
COMLPTn,
L,
LP,
N,
NU,
P, /* "PRN" */
PR,
LDOT, /* leading '.' */
DOT, /* '.' in a non-leading position */
H, /* ".h" */
HGDI, /* ".hg", ".d", or ".i" */
SPACE,
DEFAULT, /* byte of a path component after the first */
}
/* state machine for dir-encoding */
#[allow(non_camel_case_types)]
enum dir_state {
DDOT,
DH,
DHGDI,
DDEFAULT,
}
fn inset(bitset: &[u32; 8], c: u8) -> bool {
bitset[(c as usize) >> 5] & (1 << (c & 31)) != 0
}
fn charcopy(dest: Option<&mut [u8]>, destlen: &mut usize, c: u8) {
if let Some(slice) = dest {
slice[*destlen] = c
}
*destlen += 1
}
fn memcopy(dest: Option<&mut [u8]>, destlen: &mut usize, src: &[u8]) {
if let Some(slice) = dest {
slice[*destlen..*destlen + src.len()].copy_from_slice(src)
}
*destlen += src.len();
}
fn rewrap_option<'a, 'b: 'a>(
x: &'a mut Option<&'b mut [u8]>,
) -> Option<&'a mut [u8]> {
match x {
None => None,
Some(y) => Some(y),
}
}
fn hexencode<'a>(mut dest: Option<&'a mut [u8]>, destlen: &mut usize, c: u8) {
let hexdigit = b"0123456789abcdef";
charcopy(
rewrap_option(&mut dest),
destlen,
hexdigit[(c as usize) >> 4],
);
charcopy(dest, destlen, hexdigit[(c as usize) & 15]);
}
/* 3-byte escape: tilde followed by two hex digits */
fn escape3(mut dest: Option<&mut [u8]>, destlen: &mut usize, c: u8) {
charcopy(rewrap_option(&mut dest), destlen, b'~');
hexencode(dest, destlen, c);
}
fn encode_dir(mut dest: Option<&mut [u8]>, src: &[u8]) -> usize {
let mut state = dir_state::DDEFAULT;
let mut i = 0;
let mut destlen = 0;
while i < src.len() {
match state {
dir_state::DDOT => match src[i] {
b'd' | b'i' => {
state = dir_state::DHGDI;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'h' => {
state = dir_state::DH;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
_ => {
state = dir_state::DDEFAULT;
}
},
dir_state::DH => {
if src[i] == b'g' {
state = dir_state::DHGDI;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = dir_state::DDEFAULT;
}
}
dir_state::DHGDI => {
if src[i] == b'/' {
memcopy(rewrap_option(&mut dest), &mut destlen, b".hg");
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
state = dir_state::DDEFAULT;
}
dir_state::DDEFAULT => {
if src[i] == b'.' {
state = dir_state::DDOT
}
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
}
}
destlen
}
fn _encode(
twobytes: &[u32; 8],
onebyte: &[u32; 8],
mut dest: Option<&mut [u8]>,
src: &[u8],
encodedir: bool,
) -> usize {
let mut state = path_state::START;
let mut i = 0;
let mut destlen = 0;
let len = src.len();
while i < len {
match state {
path_state::START => match src[i] {
b'/' => {
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'.' => {
state = path_state::LDOT;
escape3(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b' ' => {
state = path_state::DEFAULT;
escape3(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'a' => {
state = path_state::A;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'c' => {
state = path_state::C;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'l' => {
state = path_state::L;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'n' => {
state = path_state::N;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'p' => {
state = path_state::P;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
_ => {
state = path_state::DEFAULT;
}
},
path_state::A => {
if src[i] == b'u' {
state = path_state::AU;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::AU => {
if src[i] == b'x' {
state = path_state::THIRD;
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::THIRD => {
state = path_state::DEFAULT;
match src[i] {
b'.' | b'/' | b'\0' => escape3(
rewrap_option(&mut dest),
&mut destlen,
src[i - 1],
),
_ => i -= 1,
}
}
path_state::C => {
if src[i] == b'o' {
state = path_state::CO;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::CO => {
if src[i] == b'm' {
state = path_state::COMLPT;
i += 1;
} else if src[i] == b'n' {
state = path_state::THIRD;
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::COMLPT => {
if src[i] >= b'1' && src[i] <= b'9' {
state = path_state::COMLPTn;
i += 1;
} else {
state = path_state::DEFAULT;
charcopy(
rewrap_option(&mut dest),
&mut destlen,
src[i - 1],
);
}
}
path_state::COMLPTn => {
state = path_state::DEFAULT;
match src[i] {
b'.' | b'/' | b'\0' => {
escape3(
rewrap_option(&mut dest),
&mut destlen,
src[i - 2],
);
charcopy(
rewrap_option(&mut dest),
&mut destlen,
src[i - 1],
);
}
_ => {
memcopy(
rewrap_option(&mut dest),
&mut destlen,
&src[i - 2..i],
);
}
}
}
path_state::L => {
if src[i] == b'p' {
state = path_state::LP;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::LP => {
if src[i] == b't' {
state = path_state::COMLPT;
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::N => {
if src[i] == b'u' {
state = path_state::NU;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::NU => {
if src[i] == b'l' {
state = path_state::THIRD;
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::P => {
if src[i] == b'r' {
state = path_state::PR;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::PR => {
if src[i] == b'n' {
state = path_state::THIRD;
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::LDOT => match src[i] {
b'd' | b'i' => {
state = path_state::HGDI;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'h' => {
state = path_state::H;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
_ => {
state = path_state::DEFAULT;
}
},
path_state::DOT => match src[i] {
b'/' | b'\0' => {
state = path_state::START;
memcopy(rewrap_option(&mut dest), &mut destlen, b"~2e");
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'd' | b'i' => {
state = path_state::HGDI;
charcopy(rewrap_option(&mut dest), &mut destlen, b'.');
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
b'h' => {
state = path_state::H;
memcopy(rewrap_option(&mut dest), &mut destlen, b".h");
i += 1;
}
_ => {
state = path_state::DEFAULT;
charcopy(rewrap_option(&mut dest), &mut destlen, b'.');
}
},
path_state::H => {
if src[i] == b'g' {
state = path_state::HGDI;
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
} else {
state = path_state::DEFAULT;
}
}
path_state::HGDI => {
if src[i] == b'/' {
state = path_state::START;
if encodedir {
memcopy(
rewrap_option(&mut dest),
&mut destlen,
b".hg",
);
}
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1
} else {
state = path_state::DEFAULT;
}
}
path_state::SPACE => match src[i] {
b'/' | b'\0' => {
state = path_state::START;
memcopy(rewrap_option(&mut dest), &mut destlen, b"~20");
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
_ => {
state = path_state::DEFAULT;
charcopy(rewrap_option(&mut dest), &mut destlen, b' ');
}
},
path_state::DEFAULT => {
while i != len && inset(onebyte, src[i]) {
charcopy(rewrap_option(&mut dest), &mut destlen, src[i]);
i += 1;
}
if i == len {
break;
}
match src[i] {
b'.' => {
state = path_state::DOT;
i += 1
}
b' ' => {
state = path_state::SPACE;
i += 1
}
b'/' => {
state = path_state::START;
charcopy(rewrap_option(&mut dest), &mut destlen, b'/');
i += 1;
}
_ => {
if inset(onebyte, src[i]) {
loop {
charcopy(
rewrap_option(&mut dest),
&mut destlen,
src[i],
);
i += 1;
if !(i < len && inset(onebyte, src[i])) {
break;
}
}
} else if inset(twobytes, src[i]) {
let c = src[i];
i += 1;
charcopy(
rewrap_option(&mut dest),
&mut destlen,
b'_',
);
charcopy(
rewrap_option(&mut dest),
&mut destlen,
if c == b'_' { b'_' } else { c + 32 },
);
} else {
escape3(
rewrap_option(&mut dest),
&mut destlen,
src[i],
);
i += 1;
}
}
}
}
}
}
match state {
path_state::START => (),
path_state::A => (),
path_state::AU => (),
path_state::THIRD => {
escape3(rewrap_option(&mut dest), &mut destlen, src[i - 1])
}
path_state::C => (),
path_state::CO => (),
path_state::COMLPT => {
charcopy(rewrap_option(&mut dest), &mut destlen, src[i - 1])
}
path_state::COMLPTn => {
escape3(rewrap_option(&mut dest), &mut destlen, src[i - 2]);
charcopy(rewrap_option(&mut dest), &mut destlen, src[i - 1]);
}
path_state::L => (),
path_state::LP => (),
path_state::N => (),
path_state::NU => (),
path_state::P => (),
path_state::PR => (),
path_state::LDOT => (),
path_state::DOT => {
memcopy(rewrap_option(&mut dest), &mut destlen, b"~2e");
}
path_state::H => (),
path_state::HGDI => (),
path_state::SPACE => {
memcopy(rewrap_option(&mut dest), &mut destlen, b"~20");
}
path_state::DEFAULT => (),
};
destlen
}
fn basic_encode(dest: Option<&mut [u8]>, src: &[u8]) -> usize {
let twobytes: [u32; 8] = [0, 0, 0x87ff_fffe, 0, 0, 0, 0, 0];
let onebyte: [u32; 8] =
[1, 0x2bff_3bfa, 0x6800_0001, 0x2fff_ffff, 0, 0, 0, 0];
_encode(&twobytes, &onebyte, dest, src, true)
}
const MAXSTOREPATHLEN: usize = 120;
fn lower_encode(mut dest: Option<&mut [u8]>, src: &[u8]) -> usize {
let onebyte: [u32; 8] =
[1, 0x2bff_fbfb, 0xe800_0001, 0x2fff_ffff, 0, 0, 0, 0];
let lower: [u32; 8] = [0, 0, 0x07ff_fffe, 0, 0, 0, 0, 0];
let mut destlen = 0;
for c in src {
if inset(&onebyte, *c) {
charcopy(rewrap_option(&mut dest), &mut destlen, *c)
} else if inset(&lower, *c) {
charcopy(rewrap_option(&mut dest), &mut destlen, *c + 32)
} else {
escape3(rewrap_option(&mut dest), &mut destlen, *c)
}
}
destlen
}
fn aux_encode(dest: Option<&mut [u8]>, src: &[u8]) -> usize {
let twobytes = [0; 8];
let onebyte: [u32; 8] = [!0, 0xffff_3ffe, !0, !0, !0, !0, !0, !0];
_encode(&twobytes, &onebyte, dest, src, false)
}
fn hash_mangle(src: &[u8], sha: &[u8]) -> Vec<u8> {
let dirprefixlen = 8;
let maxshortdirslen = 68;
let mut destlen = 0;
let last_slash = src.iter().rposition(|b| *b == b'/');
let last_dot: Option<usize> = {
let s = last_slash.unwrap_or(0);
src[s..]
.iter()
.rposition(|b| *b == b'.')
.and_then(|i| Some(i + s))
};
let mut dest = vec![0; MAXSTOREPATHLEN];
memcopy(Some(&mut dest), &mut destlen, b"dh/");
{
let mut first = true;
for slice in src[..last_slash.unwrap_or_else(|| src.len())]
.split(|b| *b == b'/')
{
let slice = &slice[..std::cmp::min(slice.len(), dirprefixlen)];
if destlen + (slice.len() + if first { 0 } else { 1 })
> maxshortdirslen + 3
{
break;
} else {
if !first {
charcopy(Some(&mut dest), &mut destlen, b'/')
};
memcopy(Some(&mut dest), &mut destlen, slice);
if dest[destlen - 1] == b'.' || dest[destlen - 1] == b' ' {
dest[destlen - 1] = b'_'
}
}
first = false;
}
if !first {
charcopy(Some(&mut dest), &mut destlen, b'/');
}
}
let used = destlen + 40 + {
if let Some(l) = last_dot {
src.len() - l
} else {
0
}
};
if MAXSTOREPATHLEN > used {
let slop = MAXSTOREPATHLEN - used;
let basenamelen = match last_slash {
Some(l) => src.len() - l - 1,
None => src.len(),
};
let basenamelen = std::cmp::min(basenamelen, slop);
if basenamelen > 0 {
let start = match last_slash {
Some(l) => l + 1,
None => 0,
};
memcopy(
Some(&mut dest),
&mut destlen,
&src[start..][..basenamelen],
)
}
}
for c in sha {
hexencode(Some(&mut dest), &mut destlen, *c);
}
if let Some(l) = last_dot {
memcopy(Some(&mut dest), &mut destlen, &src[l..]);
}
if destlen == dest.len() {
dest
} else {
// sometimes the path are shorter than MAXSTOREPATHLEN
dest[..destlen].to_vec()
}
}
const MAXENCODE: usize = 4096 * 4;
fn hash_encode(src: &[u8]) -> Vec<u8> {
let dired = &mut [0; MAXENCODE];
let lowered = &mut [0; MAXENCODE];
let auxed = &mut [0; MAXENCODE];
let baselen = (src.len() - 5) * 3;
if baselen >= MAXENCODE {
panic!("path_encode::hash_encore: string too long: {}", baselen)
};
let dirlen = encode_dir(Some(&mut dired[..]), src);
let sha = {
let mut hasher = Sha1::new();
hasher.input(&dired[..dirlen]);
let mut hash = vec![0; 20];
hasher.result(&mut hash);
hash
};
let lowerlen = lower_encode(Some(&mut lowered[..]), &dired[..dirlen][5..]);
let auxlen = aux_encode(Some(&mut auxed[..]), &lowered[..lowerlen]);
hash_mangle(&auxed[..auxlen], &sha)
}
pub fn path_encode(path: &[u8]) -> Vec<u8> {
let newlen = if path.len() <= MAXSTOREPATHLEN {
basic_encode(None, path)
} else {
MAXSTOREPATHLEN + 1
};
if newlen <= MAXSTOREPATHLEN {
if newlen == path.len() {
path.to_vec()
} else {
let mut res = vec![0; newlen];
basic_encode(Some(&mut res), path);
res
}
} else {
hash_encode(&path)
}
}