barrier/synergy/CProtocolUtil.cpp
2002-06-17 13:31:21 +00:00

375 lines
7.6 KiB
C++

#include "CProtocolUtil.h"
#include "IInputStream.h"
#include "IOutputStream.h"
#include "CLog.h"
#include <cctype>
#include <cstring>
//
// CProtocolUtil
//
void
CProtocolUtil::writef(IOutputStream* stream, const char* fmt, ...)
{
assert(stream != NULL);
assert(fmt != NULL);
log((CLOG_DEBUG2 "writef(%s)", fmt));
va_list args;
// determine total size to write
va_start(args, fmt);
UInt32 count = getLength(fmt, args);
va_end(args);
// done if nothing to write
if (count == 0) {
return;
}
// fill buffer
UInt8* buffer = new UInt8[count];
va_start(args, fmt);
writef(buffer, fmt, args);
va_end(args);
// write buffer
UInt8* scan = buffer;
while (count > 0) {
const UInt32 n = stream->write(scan, count);
log((CLOG_DEBUG2 "wrote %d of %d bytes", n, count));
count -= n;
scan += n;
}
delete[] buffer;
}
void
CProtocolUtil::readf(IInputStream* stream, const char* fmt, ...)
{
assert(stream != NULL);
assert(fmt != NULL);
log((CLOG_DEBUG2 "readf(%s)", fmt));
va_list args;
va_start(args, fmt);
// begin scanning
while (*fmt) {
if (*fmt == '%') {
// format specifier. determine argument size.
++fmt;
UInt32 len = eatLength(&fmt);
switch (*fmt) {
case 'i': {
// check for valid length
assert(len == 1 || len == 2 || len == 4);
// read the data
UInt8 buffer[4];
read(stream, buffer, len);
// convert it
void* v = va_arg(args, void*);
switch (len) {
case 1:
// 1 byte integer
*reinterpret_cast<UInt8*>(v) = buffer[0];
log((CLOG_DEBUG2 "readf: read %d byte integer: %d (0x%x)", len, *reinterpret_cast<UInt8*>(v), *reinterpret_cast<UInt8*>(v)));
break;
case 2:
// 2 byte integer
*reinterpret_cast<UInt16*>(v) =
static_cast<UInt16>(
(static_cast<UInt16>(buffer[0]) << 8) |
static_cast<UInt16>(buffer[1]));
log((CLOG_DEBUG2 "readf: read %d byte integer: %d (0x%x)", len, *reinterpret_cast<UInt16*>(v), *reinterpret_cast<UInt16*>(v)));
break;
case 4:
// 4 byte integer
*reinterpret_cast<UInt32*>(v) =
(static_cast<UInt32>(buffer[0]) << 24) |
(static_cast<UInt32>(buffer[1]) << 16) |
(static_cast<UInt32>(buffer[2]) << 8) |
static_cast<UInt32>(buffer[3]);
log((CLOG_DEBUG2 "readf: read %d byte integer: %d (0x%x)", len, *reinterpret_cast<UInt32*>(v), *reinterpret_cast<UInt32*>(v)));
break;
}
break;
}
case 's': {
assert(len == 0);
// read the string length
UInt8 buffer[128];
read(stream, buffer, 4);
UInt32 len = (static_cast<UInt32>(buffer[0]) << 24) |
(static_cast<UInt32>(buffer[1]) << 16) |
(static_cast<UInt32>(buffer[2]) << 8) |
static_cast<UInt32>(buffer[3]);
// use a fixed size buffer if its big enough
const bool useFixed = (len <= sizeof(buffer));
// allocate a buffer to read the data
UInt8* sBuffer;
if (useFixed) {
sBuffer = buffer;
}
else {
sBuffer = new UInt8[len];
}
// read the data
try {
read(stream, sBuffer, len);
}
catch (...) {
if (!useFixed) {
delete[] sBuffer;
}
throw;
}
log((CLOG_DEBUG2 "readf: read %d byte string: %.*s", len, len, sBuffer));
// save the data
CString* dst = va_arg(args, CString*);
dst->assign((const char*)sBuffer, len);
// release the buffer
if (!useFixed) {
delete[] sBuffer;
}
break;
}
case '%':
assert(len == 0);
break;
default:
assert(0 && "invalid format specifier");
}
// next format character
++fmt;
}
else {
// read next character
char buffer[1];
read(stream, buffer, 1);
// verify match
if (buffer[0] != *fmt) {
log((CLOG_DEBUG2 "readf: format mismatch: %c vs %c", *fmt, buffer[0]));
throw XIOReadMismatch();
}
// next format character
++fmt;
}
}
va_end(args);
}
UInt32
CProtocolUtil::getLength(const char* fmt, va_list args)
{
UInt32 n = 0;
while (*fmt) {
if (*fmt == '%') {
// format specifier. determine argument size.
++fmt;
UInt32 len = eatLength(&fmt);
switch (*fmt) {
case 'i':
assert(len == 1 || len == 2 || len == 4);
(void)va_arg(args, UInt32);
break;
case 's':
assert(len == 0);
len = (va_arg(args, CString*))->size() + 4;
(void)va_arg(args, UInt8*);
break;
case 'S':
assert(len == 0);
len = va_arg(args, UInt32) + 4;
(void)va_arg(args, UInt8*);
break;
case '%':
assert(len == 0);
len = 1;
break;
default:
assert(0 && "invalid format specifier");
}
// accumulate size
n += len;
++fmt;
}
else {
// regular character
++n;
++fmt;
}
}
return n;
}
void
CProtocolUtil::writef(void* buffer, const char* fmt, va_list args)
{
UInt8* dst = reinterpret_cast<UInt8*>(buffer);
while (*fmt) {
if (*fmt == '%') {
// format specifier. determine argument size.
++fmt;
UInt32 len = eatLength(&fmt);
switch (*fmt) {
case 'i': {
const UInt32 v = va_arg(args, UInt32);
switch (len) {
case 1:
// 1 byte integer
*dst++ = static_cast<UInt8>(v & 0xff);
break;
case 2:
// 2 byte integer
*dst++ = static_cast<UInt8>((v >> 8) & 0xff);
*dst++ = static_cast<UInt8>( v & 0xff);
break;
case 4:
// 4 byte integer
*dst++ = static_cast<UInt8>((v >> 24) & 0xff);
*dst++ = static_cast<UInt8>((v >> 16) & 0xff);
*dst++ = static_cast<UInt8>((v >> 8) & 0xff);
*dst++ = static_cast<UInt8>( v & 0xff);
break;
default:
assert(0 && "invalid integer format length");
return;
}
break;
}
case 's': {
assert(len == 0);
const CString* src = va_arg(args, CString*);
const UInt32 len = (src != NULL) ? src->size() : 0;
*dst++ = static_cast<UInt8>((len >> 24) & 0xff);
*dst++ = static_cast<UInt8>((len >> 16) & 0xff);
*dst++ = static_cast<UInt8>((len >> 8) & 0xff);
*dst++ = static_cast<UInt8>( len & 0xff);
if (len != 0) {
memcpy(dst, src->data(), len);
dst += len;
}
break;
}
case 'S': {
assert(len == 0);
const UInt32 len = va_arg(args, UInt32);
const UInt8* src = va_arg(args, UInt8*);
*dst++ = static_cast<UInt8>((len >> 24) & 0xff);
*dst++ = static_cast<UInt8>((len >> 16) & 0xff);
*dst++ = static_cast<UInt8>((len >> 8) & 0xff);
*dst++ = static_cast<UInt8>( len & 0xff);
memcpy(dst, src, len);
dst += len;
break;
}
case '%':
assert(len == 0);
*dst++ = '%';
break;
default:
assert(0 && "invalid format specifier");
}
// next format character
++fmt;
}
else {
// copy regular character
*dst++ = *fmt++;
}
}
}
UInt32
CProtocolUtil::eatLength(const char** pfmt)
{
const char* fmt = *pfmt;
UInt32 n = 0;
for (;;) {
UInt32 d;
switch (*fmt) {
case '0': d = 0; break;
case '1': d = 1; break;
case '2': d = 2; break;
case '3': d = 3; break;
case '4': d = 4; break;
case '5': d = 5; break;
case '6': d = 6; break;
case '7': d = 7; break;
case '8': d = 8; break;
case '9': d = 9; break;
default: *pfmt = fmt; return n;
}
n = 10 * n + d;
++fmt;
}
}
void
CProtocolUtil::read(IInputStream* stream, void* vbuffer, UInt32 count)
{
assert(stream != NULL);
assert(vbuffer != NULL);
UInt8* buffer = reinterpret_cast<UInt8*>(vbuffer);
while (count > 0) {
// read more
UInt32 n = stream->read(buffer, count);
// bail if stream has hungup
if (n == 0) {
log((CLOG_DEBUG2 "unexpected disconnect in readf(), %d bytes left", count));
throw XIOEndOfStream();
}
// prepare for next read
buffer += n;
count -= n;
}
}
//
// XIOReadMismatch
//
CString
XIOReadMismatch::getWhat() const throw()
{
return "CProtocolUtil::readf() mismatch";
}