intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 61 insertions, 0 deletions

diff --git a/library/cpp/protobuf/util/path.cpp b/library/cpp/protobuf/util/path.cpp
new file mode 100644
index 0000000000..efa2a42c8a
--- /dev/null
+++ b/library/cpp/protobuf/util/path.cpp
@@ -0,0 +1,61 @@
+#include "path.h"
+
+#include <util/generic/yexception.h>
+
+namespace NProtoBuf {
+    TFieldPath::TFieldPath() {
+    }
+
+    TFieldPath::TFieldPath(const Descriptor* msgType, const TStringBuf& path) {
+        Init(msgType, path);
+    }
+
+    TFieldPath::TFieldPath(const TVector<const FieldDescriptor*>& path)
+        : Path(path)
+    {
+    }
+
+    bool TFieldPath::InitUnsafe(const Descriptor* msgType, TStringBuf path) {
+        Path.clear();
+        while (path) {
+            TStringBuf next;
+            while (!next && path)
+                next = path.NextTok('/');
+            if (!next)
+                return true;
+
+            if (!msgType) // need field but no message type
+                return false;
+
+            TString nextStr(next);
+            const FieldDescriptor* field = msgType->FindFieldByName(nextStr);
+            if (!field) {
+                // Try to find extension field by FindAllExtensions()
+                const DescriptorPool* pool = msgType->file()->pool();
+                Y_ASSERT(pool); // never NULL by protobuf docs
+                TVector<const FieldDescriptor*> extensions;
+                pool->FindAllExtensions(msgType, &extensions); // find all extensions of this extendee
+                for (const FieldDescriptor* ext : extensions) {
+                    if (ext->full_name() == nextStr || ext->name() == nextStr) {
+                        if (field)
+                            return false; // ambiguity
+                        field = ext;
+                    }
+                }
+            }
+
+            if (!field)
+                return false;
+
+            Path.push_back(field);
+            msgType = field->type() == FieldDescriptor::TYPE_MESSAGE ? field->message_type() : nullptr;
+        }
+        return true;
+    }
+
+    void TFieldPath::Init(const Descriptor* msgType, const TStringBuf& path) {
+        if (!InitUnsafe(msgType, path))
+            ythrow yexception() << "Failed to resolve path \"" << path << "\" relative to " << msgType->full_name();
+    }
+
+}