feat: support locate(substr, str[, pos]) function(4paradigm#820)

howdb · May 30, 2024 · dab104b · dab104b
1 parent 59d79f6
commit dab104b
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diff --git a/hybridse/src/codegen/udf_ir_builder_test.cc b/hybridse/src/codegen/udf_ir_builder_test.cc
@@ -766,6 +766,30 @@ TEST_F(UdfIRBuilderTest, SubstringPosUdfTest) {
                                             StringRef("1234567890"), -12);
 }
 
+TEST_F(UdfIRBuilderTest, LocateUdfTest) {
+    CheckUdf<int32_t, StringRef, StringRef>("locate", 1, StringRef("ab"), StringRef("abcab"));
+    CheckUdf<int32_t, StringRef, StringRef>("locate", 3, StringRef("ab"), StringRef("bcab"));
+    CheckUdf<int32_t, StringRef, StringRef>("locate", 0, StringRef("ab"), StringRef("bcAb"));
+    CheckUdf<int32_t, StringRef, StringRef>("locate", 1, StringRef(""), StringRef(""));
+}
+
+TEST_F(UdfIRBuilderTest, LocatePosUdfTest) {
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef("ab"), StringRef("ab"), -1);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef("ab"), StringRef("Ab"), 1);
+
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 4, StringRef("ab"), StringRef("abcab"), 2);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef("ab"), StringRef("abcAb"), 2);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 4, StringRef("ab"), StringRef("abcab"), 2);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef("ab"), StringRef("abcab"), 6);
+
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 5, StringRef(""), StringRef("abcab"), 5);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 6, StringRef(""), StringRef("abcab"), 6);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef(""), StringRef("abcab"), 7);
+
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 1, StringRef(""), StringRef(""), 1);
+    CheckUdf<int32_t, StringRef, StringRef, int32_t>("locate", 0, StringRef(""), StringRef(""), 2);
+}
+
 TEST_F(UdfIRBuilderTest, UpperUcase) {
     CheckUdf<Nullable<StringRef>, Nullable<StringRef>>("upper", StringRef("SQL"), StringRef("Sql"));
     CheckUdf<Nullable<StringRef>, Nullable<StringRef>>("ucase", StringRef("SQL"), StringRef("Sql"));

diff --git a/hybridse/src/udf/default_udf_library.cc b/hybridse/src/udf/default_udf_library.cc
@@ -911,6 +911,47 @@ void DefaultUdfLibrary::InitStringUdf() {
 
     RegisterAlias("substr", "substring");
 
+    RegisterExternal("locate")
+    .args<StringRef, StringRef>(
+        static_cast<int32_t (*)(StringRef*, StringRef*)>(udf::v1::locate))
+    .doc(R"(
+        @brief Returns the position of the first occurrence of substr in str. The given pos and return value are 1-based.
+                This is a version of the `locate` function where `pos` has a default value of 1.
+
+        Example:
+
+        @code{.sql}
+
+            select locate("wo", "hello world");
+            --output 7
+            
+        @endcode)");
+
+    RegisterExternal("locate")
+        .args<StringRef, StringRef, int32_t>(
+            static_cast<int32_t (*)(StringRef*, StringRef*, int32_t)>(udf::v1::locate))
+        .doc(R"(
+            @brief Returns the position of the first occurrence of substr in str after position pos. The given pos and return value are 1-based.
+
+            Example:
+
+            @code{.sql}
+
+                select locate("wo", "hello world", 2);
+                --output 7
+                
+                select locate("Wo", "hello world", 2);
+                --output 0
+                
+            @endcode
+
+            @param substr
+            @param str
+            @param pos: define the begining search position of the str.
+             - Negetive value is illegal and will return 0 directly;
+             - If substr is "" and pos less equal len(str) + 1, return pos, other case return 0;
+        )");
+
     RegisterExternal("strcmp")
         .args<StringRef, StringRef>(
             static_cast<int32_t (*)(StringRef*, StringRef*)>(

diff --git a/hybridse/src/udf/udf.cc b/hybridse/src/udf/udf.cc
@@ -1083,6 +1083,42 @@ void sub_string(StringRef *str, int32_t from, int32_t len,
     output->size_ = static_cast<uint32_t>(len);
     return;
 }
+
+int32_t locate(StringRef *substr, StringRef *str) {
+    return locate(substr, str, 1);
+}
+
+int32_t locate(StringRef *substr, StringRef *str, int32_t pos) {
+    if (nullptr == substr || nullptr == str) {
+        return 0;
+    }
+    // negetive pos return 0 directly
+    if (pos <= 0) {
+        return 0;
+    }
+    uint32_t sub_size = substr->size_;
+    uint32_t size = str->size_;
+    // if substr is "" and pos <= len(str) + 1, return pos, other case return 0
+    if (pos + sub_size - 1 > size) {
+        return 0;
+    }
+    if (sub_size == 0) {
+        return pos;
+    }
+    for (uint32_t i = pos - 1; i <= size - sub_size; i++) {
+        uint32_t j = 0, k = i;
+        for (; j < sub_size; j++, k++) {
+            if (str->data_[k] != substr->data_[j]) {
+                break;
+            }
+        }
+        if (j == sub_size) {
+            return i + 1;
+        }
+    }
+    return 0;
+}
+
 int32_t strcmp(StringRef *s1, StringRef *s2) {
     if (s1 == s2) {
         return 0;

diff --git a/hybridse/src/udf/udf.h b/hybridse/src/udf/udf.h
@@ -390,6 +390,8 @@ void sub_string(StringRef *str, int32_t pos,
                 StringRef *output);
 void sub_string(StringRef *str, int32_t pos, int32_t len,
                 StringRef *output);
+int32_t locate(StringRef *substr, StringRef* str);
+int32_t locate(StringRef *substr, StringRef* str, int32_t pos);
 int32_t strcmp(StringRef *s1, StringRef *s2);
 void bool_to_string(bool v, StringRef *output);