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Simplify read helpers.

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Use similar APIs like https://en.cppreference.com/w/cpp/string/byte/strstr
This commit is contained in:
Amos Bird 2018-08-25 23:32:55 +08:00
parent 046137f9c5
commit 9623e59870
2 changed files with 24 additions and 20 deletions
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38
dbms/src/IO/ReadHelpers.cpp
View File

@ -175,10 +175,10 @@ void readStringInto(Vector & s, ReadBuffer & buf)
{
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\t', '\n'>(buf.position(), buf.buffer().end());
char * next_pos = find_first_symbols<'\t', '\n'>(buf.position(), buf.buffer().end());
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position(); /// Code looks complicated, because "buf.position() = next_pos" doens't work due to const-ness.
buf.position() = next_pos;
if (buf.hasPendingData())
return;
@ -199,10 +199,8 @@ void readStringUntilEOFInto(Vector & s, ReadBuffer & buf)
{
while (!buf.eof())
{
size_t bytes = buf.buffer().end() - buf.position();
appendToStringOrVector(s, buf.position(), buf.position() + bytes);
buf.position() += bytes;
appendToStringOrVector(s, buf.position(), buf.buffer().end());
buf.position() = buf.buffer().end();
if (buf.hasPendingData())
return;
@ -370,10 +368,10 @@ void readEscapedStringInto(Vector & s, ReadBuffer & buf)
{
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\t', '\n', '\\'>(buf.position(), buf.buffer().end());
char * next_pos = find_first_symbols<'\t', '\n', '\\'>(buf.position(), buf.buffer().end());
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position(); /// Code looks complicated, because "buf.position() = next_pos" doens't work due to const-ness.
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -412,10 +410,10 @@ static void readAnyQuotedStringInto(Vector & s, ReadBuffer & buf)
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\\', quote>(buf.position(), buf.buffer().end());
char * next_pos = find_first_symbols<'\\', quote>(buf.position(), buf.buffer().end());
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position();
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -522,13 +520,13 @@ void readCSVStringInto(Vector & s, ReadBuffer & buf, const FormatSettings::CSV &
/// The quoted case. We are looking for the next quotation mark.
while (!buf.eof())
{
const char * next_pos = reinterpret_cast<const char *>(memchr(buf.position(), maybe_quote, buf.buffer().end() - buf.position()));
char * next_pos = reinterpret_cast<char *>(memchr(buf.position(), maybe_quote, buf.buffer().end() - buf.position()));
if (nullptr == next_pos)
next_pos = buf.buffer().end();
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position();
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -553,13 +551,13 @@ void readCSVStringInto(Vector & s, ReadBuffer & buf, const FormatSettings::CSV &
/// Unquoted case. Look for delimiter or \r or \n.
while (!buf.eof())
{
const char * next_pos = buf.position();
char * next_pos = buf.position();
while (next_pos < buf.buffer().end()
&& *next_pos != delimiter && *next_pos != '\r' && *next_pos != '\n') /// NOTE You can make a SIMD version.
++next_pos;
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position();
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -606,10 +604,10 @@ ReturnType readJSONStringInto(Vector & s, ReadBuffer & buf)
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\\', '"'>(buf.position(), buf.buffer().end());
char * next_pos = find_first_symbols<'\\', '"'>(buf.position(), buf.buffer().end());
appendToStringOrVector(s, buf.position(), next_pos);
buf.position() += next_pos - buf.position();
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -897,8 +895,8 @@ void skipToNextLineOrEOF(ReadBuffer & buf)
{
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\n'>(buf.position(), buf.buffer().end());
buf.position() += next_pos - buf.position();
char * next_pos = find_first_symbols<'\n'>(buf.position(), buf.buffer().end());
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;
@ -916,8 +914,8 @@ void skipToUnescapedNextLineOrEOF(ReadBuffer & buf)
{
while (!buf.eof())
{
const char * next_pos = find_first_symbols<'\n', '\\'>(buf.position(), buf.buffer().end());
buf.position() += next_pos - buf.position();
char * next_pos = find_first_symbols<'\n', '\\'>(buf.position(), buf.buffer().end());
buf.position() = next_pos;
if (!buf.hasPendingData())
continue;

6
libs/libcommon/include/common/find_first_symbols.h
View File

@ -144,3 +144,9 @@ inline const char * find_first_symbols(const char * begin, const char * end)
#endif
return detail::find_first_symbols_sse2<symbols...>(begin, end);
}
template <char... symbols>
inline char * find_first_symbols(char * begin, char * end)
{
return const_cast<char *>(find_first_symbols<symbols...>(const_cast<const char*>(begin), const_cast<const char*>(end)));
}