1. add method for data file

2. mark add entry method as crate private

crates/iceberg/src/spec/manifest.rs

@@ -304,26 +304,26 @@ impl ManifestWriter {
         Ok(field_stats.into_iter().map(|stat| stat.finish()).collect())
     }
 
-    fn check_entry(&self, entry: &ManifestEntry) -> Result<()> {
+    fn check_data_file(&self, data_file: &DataFile) -> Result<()> {
         match self.metadata.content {
             ManifestContentType::Data => {
-                if entry.data_file.content != DataContentType::Data {
+                if data_file.content != DataContentType::Data {
                     return Err(Error::new(
                         ErrorKind::DataInvalid,
                         format!(
                             "Content type of entry {:?} should have DataContentType::Data",
-                            entry.data_file.content
+                            data_file.content
                         ),
                     ));
                 }
             }
             ManifestContentType::Deletes => {
-                if entry.data_file.content != DataContentType::EqualityDeletes
-                    && entry.data_file.content != DataContentType::PositionDeletes
+                if data_file.content != DataContentType::EqualityDeletes
+                    && data_file.content != DataContentType::PositionDeletes
                 {
                     return Err(Error::new(
                     ErrorKind::DataInvalid,
-                    format!("Content type of entry {:?} should have DataContentType::EqualityDeletes or DataContentType::PositionDeletes", entry.data_file.content),
+                    format!("Content type of entry {:?} should have DataContentType::EqualityDeletes or DataContentType::PositionDeletes", data_file.content),
                 ));
                 }
             }
@@ -336,8 +336,8 @@ impl ManifestWriter {
     /// - Set the snapshot id to the current snapshot id
     /// - Set the sequence number to `None` if it is invalid(smaller than 0)
     /// - Set the file sequence number to `None`
-    pub fn add(&mut self, mut entry: ManifestEntry) -> Result<()> {
-        self.check_entry(&entry)?;
+    pub(crate) fn add(&mut self, mut entry: ManifestEntry) -> Result<()> {
+        self.check_data_file(&entry.data_file)?;
         if entry.sequence_number().is_some_and(|n| n >= 0) {
             entry.status = ManifestStatus::Added;
             entry.snapshot_id = Some(self.snapshot_id);
@@ -352,26 +352,92 @@ impl ManifestWriter {
         Ok(())
     }
 
+    /// Add an added entry for a file with a specific sequence number. The entry's snapshot ID will be this manifest's snapshot ID. The entry's data sequence
+    /// number will be the provided data sequence number. The entry's file sequence number will be
+    /// assigned at commit.
+    pub fn add_file(&mut self, data_file: DataFile, sequence_number: i64) -> Result<()> {
+        self.check_data_file(&data_file)?;
+        let entry = ManifestEntry {
+            status: ManifestStatus::Added,
+            snapshot_id: Some(self.snapshot_id),
+            sequence_number: (sequence_number >= 0).then_some(sequence_number),
+            file_sequence_number: None,
+            data_file,
+        };
+        self.add_entry(entry)?;
+        Ok(())
+    }
+
     /// Add a delete manifest entry. This method will update following status of the entry:
     /// - Update the entry status to `Deleted`
     /// - Set the snapshot id to the current snapshot id
-    pub fn delete(&mut self, mut entry: ManifestEntry) -> Result<()> {
-        self.check_entry(&entry)?;
+    ///
+    /// # TODO
+    /// Remove this allow later
+    #[allow(dead_code)]
+    pub(crate) fn delete(&mut self, mut entry: ManifestEntry) -> Result<()> {
+        self.check_data_file(&entry.data_file)?;
         entry.status = ManifestStatus::Deleted;
         entry.snapshot_id = Some(self.snapshot_id);
         self.add_entry(entry)?;
         Ok(())
     }
 
+    /// Add a delete manifest entry. The entry's snapshot ID will be this manifest's snapshot ID.
+    /// However, the original data and file sequence numbers of the file must be preserved when
+    /// the file is marked as deleted.
+    pub fn delete_file(
+        &mut self,
+        data_file: DataFile,
+        sequence_number: i64,
+        file_sequence_number: i64,
+    ) -> Result<()> {
+        self.check_data_file(&data_file)?;
+        let entry = ManifestEntry {
+            status: ManifestStatus::Deleted,
+            snapshot_id: Some(self.snapshot_id),
+            sequence_number: Some(sequence_number),
+            file_sequence_number: Some(file_sequence_number),
+            data_file,
+        };
+        self.add_entry(entry)?;
+        Ok(())
+    }
+
     /// Add an existing manifest entry. This method will update following status of the entry:
     /// - Update the entry status to `Existing`
-    pub fn existing(&mut self, mut entry: ManifestEntry) -> Result<()> {
-        self.check_entry(&entry)?;
+    ///
+    /// # TODO
+    /// Remove this allow later
+    #[allow(dead_code)]
+    pub(crate) fn existing(&mut self, mut entry: ManifestEntry) -> Result<()> {
+        self.check_data_file(&entry.data_file)?;
         entry.status = ManifestStatus::Existing;
         self.add_entry(entry)?;
         Ok(())
     }
 
+    /// Add an existing manifest entry. The original data and file sequence numbers, snapshot ID,
+    /// which were assigned at commit, must be preserved when adding an existing entry.
+    pub fn existing_file(
+        &mut self,
+        data_file: DataFile,
+        snapshot_id: i64,
+        sequence_number: i64,
+        file_sequence_number: i64,
+    ) -> Result<()> {
+        self.check_data_file(&data_file)?;
+        let entry = ManifestEntry {
+            status: ManifestStatus::Existing,
+            snapshot_id: Some(snapshot_id),
+            sequence_number: Some(sequence_number),
+            file_sequence_number: Some(file_sequence_number),
+            data_file,
+        };
+        self.add_entry(entry)?;
+        Ok(())
+    }
+
     fn add_entry(&mut self, entry: ManifestEntry) -> Result<()> {
         // Check if the entry has sequence number
         if (entry.status == ManifestStatus::Deleted || entry.status == ManifestStatus::Existing)