feat(puffin): Add PuffinReader

crates/iceberg/src/puffin/blob.rs

@@ -0,0 +1,38 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use std::collections::HashMap;
+
+/// A serialized form of a "compact" Theta sketch produced by the Apache DataSketches library.
+pub(crate) const APACHE_DATASKETCHES_THETA_V1: &str = "apache-datasketches-theta-v1";
+
+/// The blob
+#[derive(Debug, PartialEq, Clone)]
+pub(crate) struct Blob {
+    /// See blob types: https://iceberg.apache.org/puffin-spec/#blob-types
+    pub(crate) r#type: String,
+    /// List of field IDs the blob was computed for; the order of items is used to compute sketches stored in the blob.
+    pub(crate) fields: Vec<i32>,
+    /// ID of the Iceberg table's snapshot the blob was computed from
+    pub(crate) snapshot_id: i64,
+    /// Sequence number of the Iceberg table's snapshot the blob was computed from
+    pub(crate) sequence_number: i64,
+    /// The actual blob data
+    pub(crate) data: Vec<u8>,
+    /// Arbitrary meta-information about the blob
+    pub(crate) properties: HashMap<String, String>,
+}

crates/iceberg/src/puffin/mod.rs

@@ -21,8 +21,10 @@
 // Temporarily allowing this while crate is under active development
 #![allow(dead_code)]
 
+mod blob;
 mod compression;
 mod metadata;
+mod reader;
 
 #[cfg(test)]
 mod test_utils;

crates/iceberg/src/puffin/reader.rs

@@ -0,0 +1,126 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use crate::io::{FileRead, InputFile};
+use crate::puffin::blob::Blob;
+use crate::puffin::metadata::{BlobMetadata, FileMetadata};
+use crate::Result;
+
+/// Puffin reader
+pub(crate) struct PuffinReader {
+    input_file: InputFile,
+    file_metadata: Option<FileMetadata>,
+}
+
+impl PuffinReader {
+    /// Returns a new Puffin reader
+    pub(crate) fn new(input_file: InputFile) -> Self {
+        Self {
+            input_file,
+            file_metadata: None,
+        }
+    }
+
+    /// Returns file metadata
+    pub(crate) async fn file_metadata(&mut self) -> Result<&FileMetadata> {
+        if let Some(ref file_metadata) = self.file_metadata {
+            Ok(file_metadata)
+        } else {
+            let file_metadata = FileMetadata::read(&self.input_file).await?;
+            Ok(self.file_metadata.insert(file_metadata))
+        }
+    }
+
+    /// Returns blob
+    pub(crate) async fn blob(&self, blob_metadata: BlobMetadata) -> Result<Blob> {
+        let file_read = self.input_file.reader().await?;
+        let start = blob_metadata.offset;
+        let end = start + blob_metadata.length;
+        let bytes = file_read.read(start..end).await?.to_vec();
+        let data = blob_metadata.compression_codec.decompress(bytes)?;
+
+        Ok(Blob {
+            r#type: blob_metadata.r#type,
+            fields: blob_metadata.fields,
+            snapshot_id: blob_metadata.snapshot_id,
+            sequence_number: blob_metadata.sequence_number,
+            data,
+            properties: blob_metadata.properties,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::puffin::reader::PuffinReader;
+    use crate::puffin::test_utils::{
+        blob_0, blob_1, java_uncompressed_metric_input_file,
+        java_zstd_compressed_metric_input_file, uncompressed_metric_file_metadata,
+        zstd_compressed_metric_file_metadata,
+    };
+
+    #[tokio::test]
+    async fn test_puffin_reader_uncompressed_metric_data() {
+        let input_file = java_uncompressed_metric_input_file();
+        let mut puffin_reader = PuffinReader::new(input_file);
+
+        let file_metadata = puffin_reader.file_metadata().await.unwrap().clone();
+        assert_eq!(file_metadata, uncompressed_metric_file_metadata());
+
+        assert_eq!(
+            puffin_reader
+                .blob(file_metadata.blobs.first().unwrap().clone())
+                .await
+                .unwrap(),
+            blob_0()
+        );
+
+        assert_eq!(
+            puffin_reader
+                .blob(file_metadata.blobs.get(1).unwrap().clone())
+                .await
+                .unwrap(),
+            blob_1(),
+        )
+    }
+
+    #[tokio::test]
+    async fn test_puffin_reader_zstd_compressed_metric_data() {
+        let input_file = java_zstd_compressed_metric_input_file();
+        let mut puffin_reader = PuffinReader::new(input_file);
+
+        let file_metadata = puffin_reader.file_metadata().await.unwrap().clone();
+        assert_eq!(file_metadata, zstd_compressed_metric_file_metadata());
+
+        assert_eq!(
+            puffin_reader
+                .blob(file_metadata.blobs.first().unwrap().clone())
+                .await
+                .unwrap(),
+            blob_0()
+        );
+
+        assert_eq!(
+            puffin_reader
+                .blob(file_metadata.blobs.get(1).unwrap().clone())
+                .await
+                .unwrap(),
+            blob_1(),
+        )
+    }
+}

crates/iceberg/src/puffin/test_utils.rs

@@ -17,6 +17,7 @@
 
 use std::collections::HashMap;
 
+use super::blob::Blob;
 use crate::io::{FileIOBuilder, InputFile};
 use crate::puffin::compression::CompressionCodec;
 use crate::puffin::metadata::{BlobMetadata, FileMetadata, CREATED_BY_PROPERTY};
@@ -68,6 +69,7 @@ pub(crate) const METRIC_BLOB_0_TYPE: &str = "some-blob";
 pub(crate) const METRIC_BLOB_0_INPUT_FIELDS: [i32; 1] = [1];
 pub(crate) const METRIC_BLOB_0_SNAPSHOT_ID: i64 = 2;
 pub(crate) const METRIC_BLOB_0_SEQUENCE_NUMBER: i64 = 1;
+pub(crate) const METRIC_BLOB_0_DATA: &str = "abcdefghi";
 
 pub(crate) fn zstd_compressed_metric_blob_0_metadata() -> BlobMetadata {
     BlobMetadata {
@@ -95,10 +97,23 @@ pub(crate) fn uncompressed_metric_blob_0_metadata() -> BlobMetadata {
     }
 }
 
+pub(crate) fn blob_0() -> Blob {
+    Blob {
+        r#type: METRIC_BLOB_0_TYPE.to_string(),
+        fields: METRIC_BLOB_0_INPUT_FIELDS.to_vec(),
+        snapshot_id: METRIC_BLOB_0_SNAPSHOT_ID,
+        sequence_number: METRIC_BLOB_0_SEQUENCE_NUMBER,
+        data: METRIC_BLOB_0_DATA.as_bytes().to_vec(),
+        properties: HashMap::new(),
+    }
+}
+
 pub(crate) const METRIC_BLOB_1_TYPE: &str = "some-other-blob";
 pub(crate) const METRIC_BLOB_1_INPUT_FIELDS: [i32; 1] = [2];
 pub(crate) const METRIC_BLOB_1_SNAPSHOT_ID: i64 = 2;
 pub(crate) const METRIC_BLOB_1_SEQUENCE_NUMBER: i64 = 1;
+pub(crate) const METRIC_BLOB_1_DATA: &str =
+    "some blob \u{0000} binary data 🤯 that is not very very very very very very long, is it?";
 
 pub(crate) fn uncompressed_metric_blob_1_metadata() -> BlobMetadata {
     BlobMetadata {
@@ -126,6 +141,17 @@ pub(crate) fn zstd_compressed_metric_blob_1_metadata() -> BlobMetadata {
     }
 }
 
+pub(crate) fn blob_1() -> Blob {
+    Blob {
+        r#type: METRIC_BLOB_1_TYPE.to_string(),
+        fields: METRIC_BLOB_1_INPUT_FIELDS.to_vec(),
+        snapshot_id: METRIC_BLOB_1_SNAPSHOT_ID,
+        sequence_number: METRIC_BLOB_1_SEQUENCE_NUMBER,
+        data: METRIC_BLOB_1_DATA.as_bytes().to_vec(),
+        properties: HashMap::new(),
+    }
+}
+
 pub(crate) const CREATED_BY_PROPERTY_VALUE: &str = "Test 1234";
 
 pub(crate) fn file_properties() -> HashMap<String, String> {