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mirror of https://github.com/tumic0/GPXSee.git synced 2024-11-28 05:34:47 +01:00

A little bit more sane binary search

This commit is contained in:
Martin Tůma 2021-01-11 23:38:46 +01:00
parent cb8c19a2bc
commit 14a9c0a8cb

View File

@ -1,4 +1,4 @@
#include "bitstream.h"
#include "bitstream.h"
#include "nodfile.h"
@ -257,7 +257,7 @@ bool NODFile::nodeBlock(Handle &hdl, quint32 nodeOffset,
quint32 offsetSize = (_indexFlags & 3) + 1;
while (low <= high) {
quint32 m = ((low + high) / 2);
int m = ((low + high) / 2);
quint32 offset = _indexRecordSize * m + _indexOffset;
quint32 blockOffset, prevBlockOffset;
@ -507,40 +507,32 @@ bool NODFile::linkType(Handle &hdl, const BlockInfo &blockInfo, quint8 linkId,
quint32 offset = ((blockInfo.hdr.s10 * blockInfo.hdr.se + 7) >> 3) + 0x13
+ blockInfo.offset + _blockOffset + ((blockInfo.hdr.s0 >> 0xb) & 1)
+ blockInfo.hdr.s11 * 3;
quint32 low = 0;
quint32 high = blockInfo.hdr.s12 - 1;
quint32 pos = blockInfo.hdr.s12;
int low = 0;
int high = blockInfo.hdr.s12 - 1;
quint16 val;
if (high > 1) {
do {
pos = (low + high) / 2;
while (low <= high) {
int m = ((low + high) / 2);
if (!(seek(hdl, offset + _blockRecordSize * pos)
&& readUInt16(hdl, val)))
return false;
if ((val >> 8) <= linkId)
low = pos;
else
high = pos;
} while (low + 1 < high);
}
if (!(seek(hdl, offset + _blockRecordSize * low) && readUInt16(hdl, val)))
return false;
type = val & 0x3f;
if ((low < high) && (pos != high)) {
if (!(seek(hdl, offset + _blockRecordSize * high)
&& readUInt16(hdl, val)))
if (!(seek(hdl, offset + _blockRecordSize * m) && readUInt16(hdl, val)))
return false;
if ((val >> 8) <= linkId)
type = (val & 0x3f);
if ((val >> 8) < linkId)
low = m + 1;
else if ((val >> 8) > linkId)
high = m - 1;
else {
type = (val & 0x3f) << 8;
return true;
}
}
type <<= 8;
if (high < 0)
return false;
if (blockInfo.hdr.s12 > 1 && !(seek(hdl, offset + _blockRecordSize * high)
&& readUInt16(hdl, val)))
return false;
type = (val & 0x3f) << 8;
return true;
}