ref: 6b84c3a6548f1c577948763b0a09a7b6e2460e04
dir: /appl/lib/palmfile.b/
implement Palmfile;
#
# Copyright © 2001-2002 Vita Nuova Holdings Limited. All rights reserved.
#
# Based on ``Palm® File Format Specification'', Document Number 3008-004, 1 May 2001, by Palm Inc.
# Doc compression based on description by Paul Lucas, 18 August 1998
#
include "sys.m";
sys: Sys;
include "daytime.m";
daytime: Daytime;
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "palmfile.m";
Dbhdrlen: con 72+6;
Datahdrsize: con 4+1+3;
Resourcehdrsize: con 4+2+4;
# Exact value of "Jan 1, 1970 0:00:00 GMT" - "Jan 1, 1904 0:00:00 GMT"
Epochdelta: con 2082844800;
tzoff := 0;
init(): string
{
sys = load Sys Sys->PATH;
bufio = load Bufio Bufio->PATH;
daytime = load Daytime Daytime->PATH;
if(bufio == nil || daytime == nil)
return "can't load required module";
tzoff = daytime->local(0).tzoff;
return nil;
}
Eshort: con "file format error: too small";
Pfile.open(name: string, mode: int): (ref Pfile, string)
{
if(mode != Sys->OREAD)
return (nil, "invalid mode");
fd := sys->open(name, mode);
if(fd == nil)
return (nil, sys->sprint("%r"));
pf := mkpfile(name, mode);
(ok, d) := sys->fstat(fd);
if(ok < 0)
return (nil, sys->sprint("%r"));
length := int d.length;
if(length == 0)
return (nil, "empty file");
f := bufio->fopen(fd, mode); # automatically closed if open fails
p := array[Dbhdrlen] of byte;
if(f.read(p, Dbhdrlen) != Dbhdrlen)
return (nil, "invalid file header: too short");
ip := pf.info;
ip.name = gets(p[0:32]);
ip.attr = get2(p[32:]);
ip.version = get2(p[34:]);
ip.ctime = pilot2epoch(get4(p[36:]));
ip.mtime = pilot2epoch(get4(p[40:]));
ip.btime = pilot2epoch(get4(p[44:]));
ip.modno = get4(p[48:]);
ip.appinfo = get4(p[52:]);
ip.sortinfo = get4(p[56:]);
if(ip.appinfo < 0 || ip.sortinfo < 0 || (ip.appinfo|ip.sortinfo)&1)
return (nil, "invalid header: bad offset");
ip.dtype = xs(get4(p[60:]));
ip.creator = xs(get4(p[64:]));
pf.uidseed = ip.uidseed = get4(p[68:]);
if(get4(p[72:]) != 0)
return (nil, "chained headers not supported"); # Palm says to reject such files
nrec := get2(p[76:]);
if(nrec < 0)
return (nil, sys->sprint("invalid header: bad record count: %d", nrec));
esize := Datahdrsize;
if(ip.attr & Fresource)
esize = Resourcehdrsize;
dataoffset := length;
pf.entries = array[nrec] of ref Entry;
if(nrec > 0){
laste: ref Entry;
buf := array[esize] of byte;
for(i := 0; i < nrec; i++){
if(f.read(buf, len buf) != len buf)
return (nil, Eshort);
e := ref Entry;
if(ip.attr & Fresource){
# resource entry: type[4], id[2], offset[4]
e.name = get4(buf);
e.id = get2(buf[4:]);
e.offset = get4(buf[6:]);
e.attr = 0;
}else{
# record entry: offset[4], attr[1], id[3]
e.offset = get4(buf);
e.attr = int buf[4];
e.id = get3(buf[5:]);
e.name = 0;
}
if(laste != nil)
laste.size = e.offset - laste.offset;
laste = e;
pf.entries[i] = e;
}
if(laste != nil)
laste.size = length - laste.offset;
dataoffset = pf.entries[0].offset;
}else{
if(f.read(p, 2) != 2)
return (nil, Eshort); # discard placeholder bytes
}
n := 0;
if(ip.appinfo > 0){
n = ip.appinfo - int f.offset();
while(--n >= 0)
f.getb();
if(ip.sortinfo)
n = ip.sortinfo - ip.appinfo;
else
n = dataoffset - ip.appinfo;
pf.appinfo = array[n] of byte;
if(f.read(pf.appinfo, n) != n)
return (nil, Eshort);
}
if(ip.sortinfo > 0){
n = ip.sortinfo - int f.offset();
while(--n >= 0)
f.getb();
n = (dataoffset-ip.sortinfo)/2;
pf.sortinfo = array[n] of int;
tmp := array[2*n] of byte;
if(f.read(tmp, len tmp) != len tmp)
return (nil, Eshort);
for(i := 0; i < n; i++)
pf.sortinfo[i] = get2(tmp[2*i:]);
}
pf.f = f; # safe to save open file reference
return (pf, nil);
}
Pfile.close(pf: self ref Pfile): int
{
if(pf.f != nil){
pf.f.close();
pf.f = nil;
}
return 0;
}
Pfile.stat(pf: self ref Pfile): ref DBInfo
{
return ref *pf.info;
}
Pfile.read(pf: self ref Pfile, i: int): (ref Record, string)
{
if(i < 0 || i >= len pf.entries){
if(i == len pf.entries)
return (nil, nil); # treat as end-of-file
return (nil, "index out of range");
}
e := pf.entries[i];
r := ref Record;
r.index = i;
nb := e.size;
r.data = array[nb] of byte;
pf.f.seek(big e.offset, 0);
if(pf.f.read(r.data, nb) != nb)
return (nil, sys->sprint("%r"));
r.cat = e.attr & 16r0F;
r.attr = e.attr & 16rF0;
r.id = e.id;
r.name = e.name;
return (r, nil);
}
#Pfile.create(name: string, info: ref DBInfo): ref Pfile
#{
#}
#Pfile.wstat(pf: self ref Pfile, ip: ref DBInfo): string
#{
# if(pf.mode != Sys->OWRITE)
# return "not open for writing";
# if((ip.attr & Fresource) != (pf.info.attr & Fresource))
# return "cannot change file type";
# # copy only a subset
# pf.info.name = ip.name;
# pf.info.attr = ip.attr;
# pf.info.version = ip.version;
# pf.info.ctime = ip.ctime;
# pf.info.mtime = ip.mtime;
# pf.info.btime = ip.btime;
# pf.info.modno = ip.modno;
# pf.info.dtype = ip.dtype;
# pf.info.creator = ip.creator;
# return nil;
#}
#Pfile.setappinfo(pf: self ref Pfile, data: array of byte): string
#{
# if(pf.mode != Sys->OWRITE)
# return "not open for writing";
# pf.appinfo = array[len data] of byte;
# pf.appinfo[0:] = data;
#}
#Pfile.setsortinfo(pf: self ref Pfile, sort: array of int): string
#{
# if(pf.mode != Sys->OWRITE)
# return "not open for writing";
# pf.sortinfo = array[len sort] of int;
# pf.sortinfo[0:] = sort;
#}
#
# internal function to extend entry list if necessary, and return a
# pointer to the next available slot
#
entryensure(pf: ref Pfile, i: int): ref Entry
{
if(i < len pf.entries)
return pf.entries[i];
e := ref Entry(0, -1, 0, 0, 0);
n := len pf.entries;
if(n == 0)
n = 64;
else
n = (i+63) & ~63;
a := array[n] of ref Entry;
a[0:] = pf.entries;
a[i] = e;
pf.entries = a;
return e;
}
writefilehdr(pf: ref Pfile, mode: int, perm: int): string
{
if(len pf.entries >= 64*1024)
return "too many records for Palm file"; # is there a way to extend it?
if((f := bufio->create(pf.fname, mode, perm)) == nil)
return sys->sprint("%r");
ip := pf.info;
esize := Datahdrsize;
if(ip.attr & Fresource)
esize = Resourcehdrsize;
offset := Dbhdrlen + esize*len pf.entries + 2;
offset += 2; # placeholder bytes or gap bytes
ip.appinfo = 0;
if(len pf.appinfo > 0){
ip.appinfo = offset;
offset += len pf.appinfo;
}
ip.sortinfo = 0;
if(len pf.sortinfo > 0){
ip.sortinfo = offset;
offset += 2*len pf.sortinfo; # 2-byte entries
}
p := array[Dbhdrlen] of byte; # bigger than any entry as well
puts(p[0:32], ip.name);
put2(p[32:], ip.attr);
put2(p[34:], ip.version);
put4(p[36:], epoch2pilot(ip.ctime));
put4(p[40:], epoch2pilot(ip.mtime));
put4(p[44:], epoch2pilot(ip.btime));
put4(p[48:], ip.modno);
put4(p[52:], ip.appinfo);
put4(p[56:], ip.sortinfo);
put4(p[60:], sx(ip.dtype));
put4(p[64:], sx(ip.creator));
put4(p[68:], pf.uidseed);
put4(p[72:], 0); # next record list ID
put2(p[76:], len pf.entries);
if(f.write(p, Dbhdrlen) != Dbhdrlen)
return ewrite(f);
if(len pf.entries > 0){
for(i := 0; i < len pf.entries; i++) {
e := pf.entries[i];
e.offset = offset;
if(ip.attr & Fresource) {
put4(p, e.name);
put2(p[4:], e.id);
put4(p[6:], e.offset);
} else {
put4(p, e.offset);
p[4] = byte e.attr;
put3(p[5:], e.id);
}
if(f.write(p, esize) != esize)
return ewrite(f);
offset += e.size;
}
}
f.putb(byte 0); # placeholder bytes (figure 1.4) or gap bytes (p. 15)
f.putb(byte 0);
if(ip.appinfo != 0){
if(f.write(pf.appinfo, len pf.appinfo) != len pf.appinfo)
return ewrite(f);
}
if(ip.sortinfo != 0){
tmp := array[2*len pf.sortinfo] of byte;
for(i := 0; i < len pf.sortinfo; i++)
put2(tmp[2*i:], pf.sortinfo[i]);
if(f.write(tmp, len tmp) != len tmp)
return ewrite(f);
}
if(f.flush() != 0)
return ewrite(f);
return nil;
}
ewrite(f: ref Iobuf): string
{
e := sys->sprint("write error: %r");
f.close();
return e;
}
Doc.open(file: ref Pfile): (ref Doc, string)
{
if(file.info.dtype != "TEXt" || file.info.creator != "REAd")
return (nil, "not a Doc file: wrong type or creator");
(r, err) := file.read(0);
if(r == nil){
if(err == nil)
err = "no directory record";
return (nil, sys->sprint("not a valid Doc file: %s", err));
}
a := r.data;
if(len a < 16)
return (nil, sys->sprint("not a valid Doc file: bad length: %d", len a));
maxrec := len file.entries-1;
d := ref Doc;
d.file = file;
d.version = get2(a);
if(d.version != 1 && d.version != 2)
err = "unknown Docfile version";
# a[2:] is spare
d.length = get4(a[4:]);
d.nrec = get2(a[8:]);
if(maxrec >= 0 && d.nrec > maxrec){
d.nrec = maxrec;
err = "invalid record count";
}
d.recsize = get2(a[10:]);
d.position = get4(a[12:]);
return (d, sys->sprint("unexpected Doc file format: %s", err));
}
Doc.iscompressed(d: self ref Doc): int
{
return (d.version&7) == 2; # high-order bits are sometimes used, ignore them
}
Doc.read(doc: self ref Doc, index: int): (string, string)
{
(r, err) := doc.file.read(index+1);
if(r == nil)
return (nil, err);
(s, serr) := doc.unpacktext(r.data);
if(s == nil)
return (nil, serr);
return (s, nil);
}
Doc.unpacktext(doc: self ref Doc, a: array of byte): (string, string)
{
nb := len a;
s: string;
if(!doc.iscompressed()){
for(i := 0; i < nb; i++)
s[len s] = int a[i]; # assumes Latin-1
return (s, nil);
}
o := 0;
for(i := 0; i < nb;){
c := int a[i++];
if(c >= 9 && c <= 16r7F || c == 0)
s[o++] = c;
else if(c >= 1 && c <= 8){
if(i+c > nb)
return (nil, "missing data in record");
while(--c >= 0)
s[o++] = int a[i++];
}else if(c >= 16rC0 && c <= 16rFF){
s[o] = ' ';
s[o+1] = c & 16r7F;
o += 2;
}else{ # c >= 0x80 && c <= 16rBF
v := int a[i++];
m := ((c & 16r3F)<<5)|(v>>3);
n := (v&7) + 3;
if(m == 0 || m > o)
return (nil, sys->sprint("data is corrupt: m=%d n=%d o=%d", m, n, o));
for(; --n >= 0; o++)
s[o] = s[o-m];
}
}
return (s, nil);
}
Doc.textlength(doc: self ref Doc, a: array of byte): int
{
nb := len a;
if(!doc.iscompressed())
return nb;
o := 0;
for(i := 0; i < nb;){
c := int a[i++];
if(c >= 9 && c <= 16r7F || c == 0)
o++;
else if(c >= 1 && c <= 8){
if(i+c > nb)
return -1;
o += c;
i += c;
}else if(c >= 16rC0 && c <= 16rFF){
o += 2;
}else{ # c >= 0x80 && c <= 16rBF
v := int a[i++];
m := ((c & 16r3F)<<5)|(v>>3);
n := (v&7) + 3;
if(m == 0 || m > o)
return -1;
o += n;
}
}
return o;
}
xs(i: int): string
{
if(i == 0)
return "";
if(i & int 16r80808080)
return sys->sprint("%8.8ux", i);
return sys->sprint("%c%c%c%c", (i>>24)&16rFF, (i>>16)&16rFF, (i>>8)&16rFF, i&16rFF);
}
sx(s: string): int
{
n := 0;
for(i := 0; i < 4; i++){
c := 0;
if(i < len s)
c = s[i] & 16rFF;
n = (n<<8) | c;
}
return n;
}
mkpfile(name: string, mode: int): ref Pfile
{
pf := ref Pfile;
pf.mode = mode;
pf.fname = name;
pf.appinfo = array[0] of byte; # making it non-nil saves having to check each access
pf.sortinfo = array[0] of int;
pf.uidseed = 0;
pf.info = DBInfo.new(name, 0, nil, 0, nil);
return pf;
}
DBInfo.new(name: string, attr: int, dtype: string, version: int, creator: string): ref DBInfo
{
info := ref DBInfo;
info.name = name;
info.attr = attr;
info.version = version;
info.ctime = daytime->now();
info.mtime = daytime->now();
info.btime = 0;
info.modno = 0;
info.appinfo = 0;
info.sortinfo = 0;
info.dtype = dtype;
info.creator = creator;
info.uidseed = 0;
info.index = 0;
info.more = 0;
return info;
}
Categories.new(labels: array of string): ref Categories
{
c := ref Categories;
c.renamed = 0;
c.lastuid = 0;
c.labels = array[16] of string;
c.uids = array[] of {0 to 15 => 0};
for(i := 0; i < len labels && i < 16; i++){
c.labels[i] = labels[i];
c.lastuid = 16r80 + i;
c.uids[i] = c.lastuid;
}
return c;
}
Categories.unpack(a: array of byte): ref Categories
{
if(len a < 16r114)
return nil; # doesn't match the structure
c := ref Categories;
c.renamed = get2(a);
c.labels = array[16] of string;
c.uids = array[16] of int;
j := 2;
for(i := 0; i < 16; i++){
c.labels[i] = latin1(a[j:j+16], 0);
j += 16;
c.uids[i] = int a[16r102+i];
}
c.lastuid = int a[16r112];
# one byte of padding is shown on p. 26, but
# two more are invariably used in practice
# before application specific data.
if(len a > 16r116)
c.appdata = a[16r116:];
return c;
}
Categories.pack(c: self ref Categories): array of byte
{
a := array[16r116 + len c.appdata] of byte;
put2(a, c.renamed);
j := 2;
for(i := 0; i < 16; i++){
puts(a[j:j+16], c.labels[i]);
j += 16;
a[16r102+i] = byte c.uids[i];
}
a[16r112] = byte c.lastuid;
a[16r113] = byte 0; # pad shown on p. 26
a[16r114] = byte 0; # extra two bytes of padding used in practice
a[16r115] = byte 0;
if(c.appdata != nil)
a[16r116:] = c.appdata;
return a;
}
Categories.mkidmap(c: self ref Categories): array of int
{
a := array[256] of {* => 0};
for(i := 0; i < len c.uids; i++)
a[c.uids[i]] = i;
return a;
}
#
# because PalmOS treats all times as local times, and doesn't associate
# them with time zones, we'll convert using local time on Plan 9 and Inferno
#
pilot2epoch(t: int): int
{
if(t == 0)
return 0; # we'll assume it's not set
return t - Epochdelta + tzoff;
}
epoch2pilot(t: int): int
{
if(t == 0)
return t;
return t - tzoff + Epochdelta;
}
#
# map Palm name to string, assuming iso-8859-1,
# but remap space and /
#
latin1(a: array of byte, remap: int): string
{
s := "";
for(i := 0; i < len a; i++){
c := int a[i];
if(c == 0)
break;
if(remap){
if(c == ' ')
c = 16r00A0; # unpaddable space
else if(c == '/')
c = 16r2215; # division /
}
s[len s] = c;
}
return s;
}
#
# map from Unicode to Palm name
#
filename(name: string): string
{
s := "";
for(i := 0; i < len name; i++){
c := name[i];
if(c == ' ')
c = 16r00A0; # unpaddable space
else if(c == '/')
c = 16r2215; # division solidus
s[len s] = c;
}
return s;
}
dbname(name: string): string
{
s := "";
for(i := 0; i < len name; i++){
c := name[i];
case c {
0 => c = ' '; # unlikely, but just in case
16r2215 => c = '/';
16r00A0 => c = ' ';
}
s[len s] = c;
}
return s;
}
#
# string conversion: can't use (string a) because
# the bytes are Latin1, not Unicode
#
gets(a: array of byte): string
{
s := "";
for(i := 0; i < len a; i++)
s[len s] = int a[i];
return s;
}
puts(a: array of byte, s: string)
{
for(i := 0; i < len a-1 && i < len s; i++)
a[i] = byte s[i];
for(; i < len a; i++)
a[i] = byte 0;
}
#
# big-endian packing
#
get4(p: array of byte): int
{
return (((((int p[0] << 8) | int p[1]) << 8) | int p[2]) << 8) | int p[3];
}
get3(p: array of byte): int
{
return (((int p[0] << 8) | int p[1]) << 8) | int p[2];
}
get2(p: array of byte): int
{
return (int p[0]<<8) | int p[1];
}
put4(p: array of byte, v: int)
{
p[0] = byte (v>>24);
p[1] = byte (v>>16);
p[2] = byte (v>>8);
p[3] = byte (v & 16rFF);
}
put3(p: array of byte, v: int)
{
p[0] = byte (v>>16);
p[1] = byte (v>>8);
p[2] = byte (v & 16rFF);
}
put2(p: array of byte, v: int)
{
p[0] = byte (v>>8);
p[1] = byte (v & 16rFF);
}