intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 76 insertions, 0 deletions

diff --git a/library/cpp/protobuf/json/util.cpp b/library/cpp/protobuf/json/util.cpp
new file mode 100644
index 0000000000..53a065eee2
--- /dev/null
+++ b/library/cpp/protobuf/json/util.cpp
@@ -0,0 +1,76 @@
+#include "util.h"
+
+#include <util/string/ascii.h>
+
+namespace {
+    void ToSnakeCaseImpl(TString* const name, std::function<bool(const char)> requiresUnderscore) {
+        bool requiresChanges = false;
+        size_t size = name->size();
+        for (size_t i = 0; i < name->size(); i++) {
+            if (IsAsciiUpper(name->at(i))) {
+                requiresChanges = true;
+                if (i > 0 && requiresUnderscore(name->at(i - 1))) {
+                    size++;
+                }
+            }
+        }
+
+        if (!requiresChanges) {
+            return;
+        }
+
+        if (size != name->size()) {
+            TString result;
+            result.reserve(size);
+            for (size_t i = 0; i < name->size(); i++) {
+                const char c = name->at(i);
+                if (IsAsciiUpper(c)) {
+                    if (i > 0 && requiresUnderscore(name->at(i - 1))) {
+                        result += '_';
+                    }
+                    result += AsciiToLower(c);
+                } else {
+                    result += c;
+                }
+            }
+            *name = std::move(result);
+        } else {
+            name->to_lower();
+        }
+    }
+}
+
+namespace NProtobufJson {
+    void ToSnakeCase(TString* const name) {
+        ToSnakeCaseImpl(name, [](const char prev) { return prev != '_'; });
+    }
+
+    void ToSnakeCaseDense(TString* const name) {
+        ToSnakeCaseImpl(name, [](const char prev) { return prev != '_' && !IsAsciiUpper(prev); });
+    }
+
+    bool EqualsIgnoringCaseAndUnderscores(TStringBuf s1, TStringBuf s2) {
+        size_t i1 = 0, i2 = 0;
+
+        while (i1 < s1.size() && i2 < s2.size()) {
+            if (s1[i1] == '_') {
+                ++i1;
+            } else if (s2[i2] == '_') {
+                ++i2;
+            } else if (AsciiToUpper(s1[i1]) != AsciiToUpper(s2[i2])) {
+                return false;
+            } else {
+                ++i1, ++i2;
+            }
+        }
+
+        while (i1 < s1.size() && s1[i1] == '_') {
+            ++i1;
+        }
+        while (i2 < s2.size() && s2[i2] == '_') {
+            ++i2;
+        }
+
+        return (i1 == s1.size() && i2 == s2.size());
+    }
+}