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Fill in flipsargs::setfiles

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Alcaro
2017-01-03 11:55:09 +01:00
parent a6b0176344
commit 3512a31797
10 changed files with 393 additions and 130 deletions
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59
patch/patch.cpp Normal file
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@@ -0,0 +1,59 @@
#include "patch.h"
namespace patch {
type identify(const file& patch)
{
byte head[16];
size_t len = patch.read(arrayview<byte>(head));
if (len>=5 && !memcmp(head, "PATCH", 5)) return t_ips;
if (len>=4 && !memcmp(head, "UPS1", 4)) return t_ups;
if (len>=4 && !memcmp(head, "BPS1", 4)) return t_bps;
return t_unknown;
}
type identify_ext(cstring path)
{
if (path.endswith(".ips")) return t_ips;
if (path.endswith(".ups")) return t_ups;
if (path.endswith(".bps")) return t_bps;
return t_unknown;
}
bool memstream::bpsnum(size_t* out)
{
//similar to uleb128, but bpsnum adds another 1<<shift for every byte except the first
//this ensures there's only one way to encode an integer
//(other than -0, but this one decodes only unsigned)
//heavily optimized, so it looks a bit weird
uint8_t b = *(at++);
if (LIKELY(b&0x80))
{
*out = b ^ (1<<7);
return true;
}
size_t tmp = b;
b = *(at++);
tmp |= b<<7;
if (LIKELY(b&0x80))
{
*out = tmp + (1<<7) - (1<<7<<7);
return true;
}
//these weird subtractions and additions wouldn't be needed if the 0x80 bits were inverted
//but I can't change the BPS spec, so they'll have to stay
size_t ret = tmp + (1<<7) + (1<<7<<7);
size_t shift = 7+7;
while (true)
{
uint8_t next = *(at++);
if (safeint<size_t>::lslov(next^0x80, shift, &tmp)) return false;
if (safeint<size_t>::addov(ret, tmp, &ret)) return false;
if (next&0x80) break;
shift+=7;
}
*out = ret;
return true;
}
}

40
patch/patch.h
View File

@@ -9,6 +9,7 @@ enum type {
t_bps
};
type identify(const file& patch);
type identify_ext(cstring path);
enum result {
e_ok,
@@ -183,43 +184,8 @@ public:
size_t remaining() { return end-at; }
//if the bpsnum is too big, number of read bytes is undefined
//does not do bounds checks, there must be at least 10 unread bytes in the buffer
bool bpsnum(size_t* out)
{
//similar to uleb128, but bpsnum adds another 1<<shift for every byte except the first
//this ensures there's only one way to encode an integer
//really heavily optimized, so it looks a bit weird
uint8_t b = *(at++);
if (LIKELY(b&0x80))
{
*out = b ^ (1<<7);
return true;
}
size_t tmp = b;
b = *(at++);
tmp |= b<<7;
if (LIKELY(b&0x80))
{
*out = tmp + (1<<7) - (1<<7<<7);
return true;
}
//these weird subtractions and additions wouldn't be needed if the 0x80 bits were inverted
//but I can't change the BPS spec, so they'll have to stay
size_t ret = tmp + (1<<7) + (1<<7<<7);
size_t shift = 7+7;
while (true)
{
uint8_t next = *(at++);
if (safeint<size_t>::lslov(next^0x80, shift, &tmp)) return false;
if (safeint<size_t>::addov(ret, tmp, &ret)) return false;
if (next&0x80) break;
shift+=7;
}
*out = ret;
return true;
}
//does not do bounds checks, there must be at least 10 unread bytes in the buffer (possibly trimmed off from checksums)
bool bpsnum(size_t* out);
};
class membufwriter {