[rfile] Add some more information in RKeyInfo

Author: silverweed

io/io/inc/ROOT/RFile.hxx

@@ -83,8 +83,17 @@ private:
    std::string fClassName;
    std::uint16_t fCycle = 0;
    ECategory fCategory = ECategory::kInvalid;
+   std::uint64_t fObjLen = 0;
+   std::uint64_t fObjNBytes = 0;
+   std::uint64_t fKeyLen = 0;
+   std::uint64_t fKeySeek = 0;
+   std::uint64_t fParentDirSeek = 0;
+
+   explicit RKeyInfo(const TKey &key);
 
 public:
+   RKeyInfo() = default;
+
    /// Returns the absolute path of this key, i.e. the directory part plus the object name.
    const std::string &GetPath() const { return fPath; }
    /// Returns the base name of this key, i.e. the name of the object without the directory part.
@@ -93,6 +102,16 @@ public:
    const std::string &GetClassName() const { return fClassName; }
    std::uint16_t GetCycle() const { return fCycle; }
    ECategory GetCategory() const { return fCategory; }
+   /// Returns the in-memory size of the uncompressed object.
+   std::uint64_t GetObjLen() const { return fObjLen; }
+   /// Returns the on-disk size of the (potentially compressed) object, excluding its key.
+   std::uint64_t GetObjNBytes() const { return fObjNBytes; }
+   /// Returns the on-disk size of this object's key.
+   std::uint64_t GetKeyLen() const { return fKeyLen; }
+   /// Returns the on-disk offset of this object's key.
+   std::uint64_t GetKeySeek() const { return fKeySeek; }
+   /// Returns the on-disk offset of this object's parent directory key.
+   std::uint64_t GetParentDirSeek() const { return fParentDirSeek; }
 };
 
 /// The iterable returned by RFile::ListKeys()

io/io/src/RFile.cxx

@@ -540,18 +540,26 @@ void RFile::Close()
    fFile.reset();
 }
 
+ROOT::Experimental::RKeyInfo::RKeyInfo(const TKey &key)
+   : fPath(ReconstructFullKeyPath(key)),
+     fTitle(key.GetTitle()),
+     fClassName(key.GetClassName()),
+     fCycle(key.GetCycle()),
+     fObjLen(key.GetObjlen()),
+     fObjNBytes(key.GetNbytes() - key.GetKeylen()),
+     fKeyLen(key.GetKeylen()),
+     fKeySeek(key.GetSeekKey()),
+     fParentDirSeek(key.GetSeekPdir())
+{
+}
+
 std::optional<ROOT::Experimental::RKeyInfo> RFile::GetKeyInfo(std::string_view path) const
 {
    const TKey *key = GetTKey(path);
    if (!key)
       return {};
 
-   RKeyInfo keyInfo;
-   keyInfo.fPath = ReconstructFullKeyPath(*key);
-   keyInfo.fClassName = key->GetClassName();
-   keyInfo.fCycle = key->GetCycle();
-   keyInfo.fTitle = key->GetTitle();
-
+   RKeyInfo keyInfo(*key);
    return keyInfo;
 }