From 15054341d8d9a36cb68042f88624b6aed4ae1b25 Mon Sep 17 00:00:00 2001
From: Smith Cruise <chendingchao1@126.com>
Date: Sat, 21 Jun 2025 10:44:15 +0800
Subject: [PATCH 1/3] [C++] Add get_metadata api in DataFileReaderBase

Signed-off-by: Smith Cruise <chendingchao1@126.com>
---
 lang/c++/include/avro/DataFile.hh | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/lang/c++/include/avro/DataFile.hh b/lang/c++/include/avro/DataFile.hh
index 8ff5d88c614..9c9eac470f5 100644
--- a/lang/c++/include/avro/DataFile.hh
+++ b/lang/c++/include/avro/DataFile.hh
@@ -54,6 +54,11 @@ const int SyncSize = 16;
  */
 typedef std::array<uint8_t, SyncSize> DataFileSync;
 
+/**
+ * The avro metadata.
+ */
+typedef std::map<std::string, std::vector<uint8_t>> Metadata;
+
 /**
  * Type-independent portion of DataFileWriter.
  *  At any given point in time, at most one file can be written using
@@ -71,8 +76,6 @@ class AVRO_DECL DataFileWriterBase {
     const DataFileSync sync_;
     int64_t objectCount_;
 
-    typedef std::map<std::string, std::vector<uint8_t>> Metadata;
-
     Metadata metadata_;
     int64_t lastSync_;
 
@@ -212,7 +215,6 @@ class AVRO_DECL DataFileReaderBase {
     ValidSchema dataSchema_;
     DecoderPtr dataDecoder_;
     std::unique_ptr<InputStream> dataStream_;
-    typedef std::map<std::string, std::vector<uint8_t>> Metadata;
 
     Metadata metadata_;
     DataFileSync sync_{};
@@ -306,6 +308,11 @@ public:
      * Return the last synchronization point before our current position.
      */
     int64_t previousSync() const;
+
+    /**
+     * Return avro's metadata
+     */
+    Metadata &metadata() { return metadata_; }
 };
 
 /**

From 3d1b1fe38208a0a115f76be9d096170a4ad25795 Mon Sep 17 00:00:00 2001
From: Smith Cruise <chendingchao1@126.com>
Date: Sun, 22 Jun 2025 14:54:42 +0800
Subject: [PATCH 2/3] improve

Signed-off-by: Smith Cruise <chendingchao1@126.com>
---
 lang/c++/include/avro/DataFile.hh | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/lang/c++/include/avro/DataFile.hh b/lang/c++/include/avro/DataFile.hh
index 9c9eac470f5..dba82a50514 100644
--- a/lang/c++/include/avro/DataFile.hh
+++ b/lang/c++/include/avro/DataFile.hh
@@ -54,11 +54,6 @@ const int SyncSize = 16;
  */
 typedef std::array<uint8_t, SyncSize> DataFileSync;
 
-/**
- * The avro metadata.
- */
-typedef std::map<std::string, std::vector<uint8_t>> Metadata;
-
 /**
  * Type-independent portion of DataFileWriter.
  *  At any given point in time, at most one file can be written using
@@ -76,6 +71,8 @@ class AVRO_DECL DataFileWriterBase {
     const DataFileSync sync_;
     int64_t objectCount_;
 
+    typedef std::map<std::string, std::vector<uint8_t>> Metadata;
+
     Metadata metadata_;
     int64_t lastSync_;
 
@@ -215,6 +212,7 @@ class AVRO_DECL DataFileReaderBase {
     ValidSchema dataSchema_;
     DecoderPtr dataDecoder_;
     std::unique_ptr<InputStream> dataStream_;
+    typedef std::map<std::string, std::vector<uint8_t>> Metadata;
 
     Metadata metadata_;
     DataFileSync sync_{};
@@ -312,7 +310,7 @@ public:
     /**
      * Return avro's metadata
      */
-    Metadata &metadata() { return metadata_; }
+    const Metadata &metadata() { return metadata_; }
 };
 
 /**

From e1fc6a03a96c795a7c3a52673dc7f2c7c2c419f3 Mon Sep 17 00:00:00 2001
From: Smith Cruise <chendingchao1@126.com>
Date: Sun, 22 Jun 2025 14:56:06 +0800
Subject: [PATCH 3/3] improve

Signed-off-by: Smith Cruise <chendingchao1@126.com>
---
 lang/c++/include/avro/DataFile.hh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lang/c++/include/avro/DataFile.hh b/lang/c++/include/avro/DataFile.hh
index dba82a50514..bcb512eaf47 100644
--- a/lang/c++/include/avro/DataFile.hh
+++ b/lang/c++/include/avro/DataFile.hh
@@ -310,7 +310,7 @@ public:
     /**
      * Return avro's metadata
      */
-    const Metadata &metadata() { return metadata_; }
+    const Metadata &metadata() const { return metadata_; }
 };
 
 /**