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fix escape character in like predicate #75

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Merged
yubingpeng merged 1 commit into from
Sep 5, 2017
Merged

fix escape character in like predicate #75

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46 changes: 34 additions & 12 deletions be/src/exprs/like_predicate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,11 @@ static const RE2 STARTS_WITH_RE(
// A regex to match any regex pattern which is equivalent to a constant string match.
static const RE2 EQUALS_RE("\\^([^\\.\\^\\{\\[\\(\\|\\)\\]\\}\\+\\*\\?\\$\\\\]*)\\$");

static const re2::RE2 LIKE_SUBSTRING_RE("(?:%+)(((\\\\%)|(\\\\_)|([^%_]))+)(?:%+)");
static const re2::RE2 LIKE_ENDS_WITH_RE("(?:%+)(((\\\\%)|(\\\\_)|([^%_]))+)");
static const re2::RE2 LIKE_STARTS_WITH_RE("(((\\\\%)|(\\\\_)|([^%_]))+)(?:%+)");
static const re2::RE2 LIKE_EQUALS_RE("(((\\\\%)|(\\\\_)|([^%_]))+)");

void LikePredicate::init() {
}

Expand All @@ -62,24 +67,24 @@ void LikePredicate::like_prepare(
return;
}
StringValue pattern = StringValue::from_string_val(pattern_val);
re2::RE2 substring_re("(?:%+)([^%_]*)(?:%+)");
re2::RE2 ends_with_re("(?:%+)([^%_]*)");
re2::RE2 starts_with_re("([^%_]*)(?:%+)");
re2::RE2 equals_re("([^%_]*)");
std::string pattern_str(pattern.ptr, pattern.len);
std::string search_string;
if (RE2::FullMatch(pattern_str, substring_re, &search_string)) {
state->set_search_string(search_string);
state->function = constant_substring_fn;
} else if (RE2::FullMatch(pattern_str, starts_with_re, &search_string)) {
state->set_search_string(search_string);
state->function = constant_starts_with_fn;
} else if (RE2::FullMatch(pattern_str, ends_with_re, &search_string)) {
if (RE2::FullMatch(pattern_str, LIKE_ENDS_WITH_RE, &search_string)) {
remove_escape_character(&search_string);
state->set_search_string(search_string);
state->function = constant_ends_with_fn;
} else if (RE2::FullMatch(pattern_str, equals_re, &search_string)) {
} else if (RE2::FullMatch(pattern_str, LIKE_SUBSTRING_RE, &search_string)) {
remove_escape_character(&search_string);
state->set_search_string(search_string);
state->function = constant_substring_fn;
} else if (RE2::FullMatch(pattern_str, LIKE_EQUALS_RE, &search_string)) {
remove_escape_character(&search_string);
state->set_search_string(search_string);
state->function = constant_equals_fn;
} else if (RE2::FullMatch(pattern_str, LIKE_STARTS_WITH_RE, &search_string)) {
remove_escape_character(&search_string);
state->set_search_string(search_string);
state->function = constant_starts_with_fn;
} else {
std::string re_pattern;
convert_like_pattern(
Expand Down Expand Up @@ -436,4 +441,21 @@ void LikePredicate::convert_like_pattern(
}
}

void LikePredicate::remove_escape_character(std::string* search_string) {
std::string tmp_search_string;
tmp_search_string.swap(*search_string);
int len = tmp_search_string.length();
for (int i = 0; i < len;) {
if (tmp_search_string[i] == '\\'
&& i + 1 < len
&& (tmp_search_string[i+1] == '%' || tmp_search_string[i+1] == '_')) {
search_string->append(1, tmp_search_string[i+1]);
i += 2;
} else {
search_string->append(1, tmp_search_string[i]);
i++;
}
}
}

}
2 changes: 2 additions & 0 deletions be/src/exprs/like_predicate.h
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Original file line number Diff line number Diff line change
Expand Up @@ -172,6 +172,8 @@ class LikePredicate {
palo_udf::FunctionContext* context,
const palo_udf::StringVal& pattern,
std::string* re_pattern);

static void remove_escape_character(std::string* search_string);
};

}
Expand Down