ref: 2459e34d77e2e21ef829c0dfaafd99433899494f
dir: /appl/lib/bufio.b/
implement Bufio;
include "sys.m";
sys: Sys;
include "bufio.m";
UTFself: con 16r80; # ascii and UTF sequences are the same (<)
Maxrune: con 8; # could probably be Sys->UTFmax
Bufsize: con Sys->ATOMICIO;
Filler: adt
{
iobuf: ref Iobuf;
fill: BufioFill;
next: cyclic ref Filler;
};
fillers: ref Filler;
create(filename: string, mode, perm: int): ref Iobuf
{
if (sys == nil)
sys = load Sys Sys->PATH;
if ((fd := sys->create(filename, mode, perm)) == nil)
return nil;
return ref Iobuf(fd, array[Bufsize+Maxrune] of byte, 0, 0, 0, big 0, big 0, mode, mode);
}
open(filename: string, mode: int): ref Iobuf
{
if (sys == nil)
sys = load Sys Sys->PATH;
if ((fd := sys->open(filename, mode)) == nil)
return nil;
return ref Iobuf(fd, array[Bufsize+Maxrune] of byte, 0, 0, 0, big 0, big 0, mode, mode);
}
fopen(fd: ref Sys->FD, mode: int): ref Iobuf
{
if (sys == nil)
sys = load Sys Sys->PATH;
if ((filpos := sys->seek(fd, big 0, 1)) < big 0)
filpos = big 0;
return ref Iobuf(fd, array[Bufsize+Maxrune] of byte, 0, 0, 0, filpos, filpos, mode, mode);
}
sopen(input: string): ref Iobuf
{
return aopen(array of byte input);
}
aopen(b: array of byte): ref Iobuf
{
if (sys == nil)
sys = load Sys Sys->PATH;
return ref Iobuf(nil, b, 0, len b, 0, big 0, big 0, OREAD, OREAD);
}
readchunk(b: ref Iobuf): int
{
if (b.fd == nil){
if ((f := filler(b)) != nil){
if ((n := f.fill->fill(b)) == EOF)
nofill(b);
return n;
}
return EOF;
}
if (b.filpos != b.bufpos + big b.size) {
s := b.bufpos + big b.size;
if (sys->seek(b.fd, s, 0) != s)
return ERROR;
b.filpos = s;
}
i := len b.buffer - b.size - 1;
if(i > Bufsize)
i = Bufsize;
if ((i = sys->read(b.fd, b.buffer[b.size:], i)) <= 0) {
if(i < 0)
return ERROR;
return EOF;
}
b.size += i;
b.filpos += big i;
return i;
}
writechunk(b: ref Iobuf): int
{
err := (b.fd == nil);
if (b.filpos != b.bufpos) {
if (sys->seek(b.fd, b.bufpos, 0) != b.bufpos)
err = 1;
b.filpos = b.bufpos;
}
if ((size := b.size) > Bufsize)
size = Bufsize;
if (sys->write(b.fd, b.buffer, size) != size)
err = 1;
b.filpos += big size;
b.size -= size;
if (b.size) {
b.dirty = 1;
b.buffer[0:] = b.buffer[Bufsize:Bufsize+b.size];
} else
b.dirty = 0;
b.bufpos += big size;
b.index -= size;
if(err)
return ERROR;
return size;
}
Iobuf.close(b: self ref Iobuf)
{
if (b.fd == nil) {
nofill(b);
return;
}
if (b.dirty)
b.flush();
b.fd = nil;
b.buffer = nil;
}
Iobuf.flush(b: self ref Iobuf): int
{
if (b.fd == nil)
return ERROR;
if (b.lastop == OREAD){
b.bufpos = b.filpos;
b.size = 0;
return 0;
}
while (b.dirty) {
if (writechunk(b) < 0)
return ERROR;
if (b.index < 0) {
b.bufpos += big b.index;
b.index = 0;
}
}
return 0;
}
Iobuf.seek(b: self ref Iobuf, off: big, start: int): big
{
npos: big;
if (b.fd == nil){
if(filler(b) != nil)
return big ERROR;
}
case (start) {
0 => # absolute address
npos = off;
1 => # offset from current location
npos = b.bufpos + big b.index + off;
off = npos;
start = Sys->SEEKSTART;
2 => # offset from EOF
npos = big -1;
* => return big ERROR;
}
if (b.bufpos <= npos && npos < b.bufpos + big b.size) {
b.index = int(npos - b.bufpos);
return npos;
}
if (b.fd == nil || b.dirty && b.flush() < 0)
return big ERROR;
b.size = 0;
b.index = 0;
if ((s := sys->seek(b.fd, off, start)) < big 0) {
b.bufpos = b.filpos;
return big ERROR;
}
b.bufpos = b.filpos = s;
return s;
}
Iobuf.offset(b: self ref Iobuf): big
{
return b.bufpos + big b.index;
}
write2read(b: ref Iobuf): int
{
while (b.dirty)
if (b.flush() < 0)
return ERROR;
b.bufpos = b.filpos;
b.size = 0;
b.lastop = OREAD;
if ((r := readchunk(b)) < 0)
return r;
if (b.index > b.size)
return EOF;
return 0;
}
Iobuf.read(b: self ref Iobuf, buf: array of byte, n: int): int
{
if (b.mode == OWRITE)
return ERROR;
if (b.lastop != OREAD){
if ((r := write2read(b)) < 0)
return r;
}
k := n;
while (b.size - b.index < k) {
buf[0:] = b.buffer[b.index:b.size];
buf = buf[b.size - b.index:];
k -= b.size - b.index;
b.bufpos += big b.size;
b.index = 0;
b.size = 0;
if ((r := readchunk(b)) < 0) {
if(r == EOF || n != k)
return n-k;
return ERROR;
}
}
buf[0:] = b.buffer[b.index:b.index+k];
b.index += k;
return n;
}
Iobuf.getb(b: self ref Iobuf): int
{
if(b.lastop != OREAD){
if(b.mode == OWRITE)
return ERROR;
if((r := write2read(b)) < 0)
return r;
}
if (b.index == b.size) {
b.bufpos += big b.index;
b.index = 0;
b.size = 0;
if ((r := readchunk(b)) < 0)
return r;
}
return int b.buffer[b.index++];
}
Iobuf.ungetb(b: self ref Iobuf): int
{
if(b.mode == OWRITE || b.lastop != OREAD)
return ERROR;
b.index--;
return 1;
}
Iobuf.getc(b: self ref Iobuf): int
{
r, i, s: int;
if(b.lastop != OREAD){
if(b.mode == OWRITE)
return ERROR;
if((r = write2read(b)) < 0)
return r;
}
for(;;) {
if(b.index < b.size) {
r = int b.buffer[b.index];
if(r < UTFself){
b.index++;
return r;
}
(r, i, s) = sys->byte2char(b.buffer[0:b.size], b.index);
if (i != 0) {
b.index += i;
return r;
}
b.buffer[0:] = b.buffer[b.index:b.size];
}
b.bufpos += big b.index;
b.size -= b.index;
b.index = 0;
if ((r = readchunk(b)) < 0)
return r;
}
# Not reached:
return -1;
}
Iobuf.ungetc(b: self ref Iobuf): int
{
if(b.index == 0 || b.mode == OWRITE || b.lastop != OREAD)
return ERROR;
stop := b.index - Sys->UTFmax;
if(stop < 0)
stop = 0;
buf := b.buffer[0:b.size];
for(i := b.index-1; i >= stop; i--){
(nil, n, s) := sys->byte2char(buf, i);
if(s && i + n == b.index){
b.index = i;
return 1;
}
}
b.index--;
return 1;
}
# optimised when term < UTFself (common case)
tgets(b: ref Iobuf, t: int): string
{
str: string;
term := byte t;
for(;;){
start := b.index;
end := start + sys->utfbytes(b.buffer[start:], b.size-start);
buf := b.buffer;
# XXX could speed up by adding extra byte to end of buffer and
# placing a sentinel there (eliminate one test, perhaps 35% speedup).
# (but not when we've been given the buffer externally)
for(i := start; i < end; i++){
if(buf[i] == term){
i++;
str += string buf[start:i];
b.index = i;
return str;
}
}
str += string buf[start:i];
if(i < b.size)
b.buffer[0:] = buf[i:b.size];
b.size -= i;
b.bufpos += big i;
b.index = 0;
if(readchunk(b) < 0)
break;
}
return str;
}
Iobuf.gets(b: self ref Iobuf, term: int): string
{
i: int;
if(b.mode == OWRITE)
return nil;
if(b.lastop != OREAD && write2read(b) < 0)
return nil;
# if(term < UTFself)
# return tgets(b, term);
str: string;
ch := -1;
for (;;) {
start := b.index;
n := 0;
while(b.index < b.size){
(ch, i, nil) = sys->byte2char(b.buffer[0:b.size], b.index);
if(i == 0) # too few bytes for full Rune
break;
n += i;
b.index += i;
if(ch == term)
break;
}
if(n > 0)
str += string b.buffer[start:start+n];
if(ch == term)
return str;
b.buffer[0:] = b.buffer[b.index:b.size];
b.bufpos += big b.index;
b.size -= b.index;
b.index = 0;
if (readchunk(b) < 0)
break;
}
return str; # nil at EOF
}
Iobuf.gett(b: self ref Iobuf, s: string): string
{
r := "";
if (b.mode == OWRITE || (ch := b.getc()) < 0)
return nil;
do {
r[len r] = ch;
for (i:=0; i<len(s); i++)
if (ch == s[i])
return r;
} while ((ch = b.getc()) >= 0);
return r;
}
read2write(b: ref Iobuf)
{
# last operation was a read
b.bufpos += big b.index;
b.size = 0;
b.index = 0;
b.lastop = OWRITE;
}
Iobuf.write(b: self ref Iobuf, buf: array of byte, n: int): int
{
if(b.lastop != OWRITE) {
if(b.mode == OREAD)
return ERROR;
read2write(b);
}
start := 0;
k := n;
while(k > 0){
nw := Bufsize - b.index;
if(nw > k)
nw = k;
end := start + nw;
b.buffer[b.index:] = buf[start:end];
start = end;
b.index += nw;
k -= nw;
if(b.index > b.size)
b.size = b.index;
b.dirty = 1;
if(b.size == Bufsize && writechunk(b) < 0)
return ERROR;
}
return n;
}
Iobuf.putb(b: self ref Iobuf, c: byte): int
{
if(b.lastop != OWRITE) {
if(b.mode == OREAD)
return ERROR;
read2write(b);
}
b.buffer[b.index++] = c;
if(b.index > b.size)
b.size = b.index;
b.dirty = 1;
if(b.size >= Bufsize) {
if (b.fd == nil)
return ERROR;
if (writechunk(b) < 0)
return ERROR;
}
return 0;
}
Iobuf.putc(b: self ref Iobuf, c: int): int
{
if(b.lastop != OWRITE) {
if (b.mode == OREAD)
return ERROR;
read2write(b);
}
if(c < UTFself)
b.buffer[b.index++] = byte c;
else
b.index += sys->char2byte(c, b.buffer, b.index);
if (b.index > b.size)
b.size = b.index;
b.dirty = 1;
if (b.size >= Bufsize) {
if (writechunk(b) < 0)
return ERROR;
}
return 0;
}
Iobuf.puts(b: self ref Iobuf, s: string): int
{
if(b.lastop != OWRITE) {
if (b.mode == OREAD)
return ERROR;
read2write(b);
}
n := len s;
if (n == 0)
return 0;
ind := b.index;
buf := b.buffer;
for(i := 0; i < n; i++){
c := s[i];
if(c < UTFself)
buf[ind++] = byte c;
else
ind += sys->char2byte(c, buf, ind);
if(ind >= Bufsize){
b.index = ind;
if(ind > b.size)
b.size = ind;
b.dirty = 1;
if(writechunk(b) < 0)
return ERROR;
ind = b.index;
}
}
b.dirty = b.index != ind;
b.index = ind;
if (ind > b.size)
b.size = ind;
return n;
}
filler(b: ref Iobuf): ref Filler
{
for (f := fillers; f != nil; f = f.next)
if(f.iobuf == b)
return f;
return nil;
}
Iobuf.setfill(b: self ref Iobuf, fill: BufioFill)
{
if ((f := filler(b)) != nil)
f.fill = fill;
else
fillers = ref Filler(b, fill, fillers);
}
nofill(b: ref Iobuf)
{
prev: ref Filler;
for(f := fillers; f != nil; f = f.next) {
if(f.iobuf == b) {
if (prev == nil)
fillers = f.next;
else
prev.next = f.next;
}
prev = f;
}
}