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Code Issues

Fixed missing BOF flag, better boundary checks, code unification

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This commit is contained in:
Dmitry Yemanov 2021-11-25 20:41:23 +03:00
parent ffef63161c
commit 067c8040b2
1 changed files with 14 additions and 23 deletions
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37
src/dsql/DsqlCursor.cpp
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@ -117,11 +117,7 @@ int DsqlCursor::fetchNext(thread_db* tdbb, UCHAR* buffer)
return 0;
}
if (m_state == EOS)
return 1;
const FB_UINT64 position = (m_state == BOS) ? 0 : m_position + 1;
return fetchFromCache(tdbb, buffer, position);
return fetchRelative(tdbb, buffer, 1);
}
int DsqlCursor::fetchPrior(thread_db* tdbb, UCHAR* buffer)
@ -129,17 +125,7 @@ int DsqlCursor::fetchPrior(thread_db* tdbb, UCHAR* buffer)
if (!(m_flags & IStatement::CURSOR_TYPE_SCROLLABLE))
(Arg::Gds(isc_invalid_fetch_option) << Arg::Str("PRIOR")).raise();
if (m_state == BOS)
return -1;
if (!m_position)
{
m_state = BOS;
return -1;
}
const FB_UINT64 position = ((m_state == EOS) ? m_cachedCount : m_position) - 1;
return fetchFromCache(tdbb, buffer, position);
return fetchRelative(tdbb, buffer, -1);
}
int DsqlCursor::fetchFirst(thread_db* tdbb, UCHAR* buffer)
@ -182,6 +168,12 @@ int DsqlCursor::fetchAbsolute(thread_db* tdbb, UCHAR* buffer, SLONG position)
offset = m_cachedCount;
}
if (position + offset < 0)
{
m_state = BOS;
return -1;
}
return fetchFromCache(tdbb, buffer, position + offset);
}
@ -190,12 +182,14 @@ int DsqlCursor::fetchRelative(thread_db* tdbb, UCHAR* buffer, SLONG offset)
if (!(m_flags & IStatement::CURSOR_TYPE_SCROLLABLE))
(Arg::Gds(isc_invalid_fetch_option) << Arg::Str("RELATIVE")).raise();
SINT64 position = m_position + offset;
if (m_state == BOS)
{
if (offset <= 0)
return -1;
return fetchFromCache(tdbb, buffer, offset - 1);
position = offset - 1;
}
else if (m_state == EOS)
{
@ -204,19 +198,16 @@ int DsqlCursor::fetchRelative(thread_db* tdbb, UCHAR* buffer, SLONG offset)
fb_assert(m_eof);
if ((SINT64) m_cachedCount + offset < 0)
return -1;
return fetchFromCache(tdbb, buffer, m_cachedCount + offset);
position = m_cachedCount + offset;
}
if ((SINT64) m_position + offset < 0)
if (position < 0)
{
m_state = BOS;
return -1;
}
return fetchFromCache(tdbb, buffer, m_position + offset);
return fetchFromCache(tdbb, buffer, position);
}
int DsqlCursor::fetchFromCache(thread_db* tdbb, UCHAR* buffer, FB_UINT64 position)