feat(binding/ocaml): Add support for operator reader and metadata (#2881

)

* add metadata and operator reader

* format code

* update reader seek api

* make lint happy

bindings/ocaml/build.rs

@@ -19,6 +19,10 @@ use std::path::PathBuf;
 
 pub fn main() -> std::io::Result<()> {
     let root = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
+
+    ocaml_build::Sigs::new("src/seek_from.ml")
+        .with_source_dir(root.join("src/seek_from"))
+        .generate()?;
     ocaml_build::Sigs::new("src/operator.ml")
         .with_source_dir(root.join("src/operator"))
         .generate()

bindings/ocaml/lib/operator.ml

@@ -18,12 +18,38 @@
 *)
 
 let new_operator = Opendal_core.Operator.operator
+let stat = Opendal_core.Operator.blocking_stat
 let is_exist = Opendal_core.Operator.blocking_is_exist
 let create_dir = Opendal_core.Operator.blocking_create_dir
 let read = Opendal_core.Operator.blocking_read
+let reader = Opendal_core.Operator.blocking_reader
 let write = Opendal_core.Operator.blocking_write
 let copy = Opendal_core.Operator.blocking_copy
 let rename = Opendal_core.Operator.blocking_rename
 let delete = Opendal_core.Operator.blocking_delete
 let remove = Opendal_core.Operator.blocking_remove
 let remove_all = Opendal_core.Operator.blocking_remove_all
+
+module Reader = struct
+  let read = Opendal_core.Operator.reader_read
+
+  let seek reader pos mode =
+    let inner_pos =
+      match mode with
+      | Unix.SEEK_CUR -> Opendal_core.Seek_from.Current pos
+      | Unix.SEEK_END -> Opendal_core.Seek_from.End pos
+      | Unix.SEEK_SET -> Opendal_core.Seek_from.Start pos
+    in
+    Opendal_core.Operator.reader_seek reader inner_pos
+end
+
+module Metadata = struct
+  let is_file = Opendal_core.Operator.metadata_is_file
+  let is_dir = Opendal_core.Operator.metadata_is_dir
+  let content_length = Opendal_core.Operator.metadata_content_length
+  let content_md5 = Opendal_core.Operator.metadata_content_md5
+  let content_type = Opendal_core.Operator.metadata_content_type
+  let content_disposition = Opendal_core.Operator.metadata_content_disposition
+  let etag = Opendal_core.Operator.metadata_etag
+  let last_modified = Opendal_core.Operator.metadata_last_modified
+end

bindings/ocaml/lib/operator.mli

@@ -28,6 +28,17 @@ val new_operator :
     @return The block operator
 *)
 
+val stat :
+  Opendal_core.Operator.operator ->
+  string ->
+  (Opendal_core.Operator.metadata, string) result
+(** [is_exist operator path] Get current path's metadata **without cache** directly.
+    
+    @param operator The operator
+    @param path want to stat
+    @return metadata
+*)
+
 val is_exist : Opendal_core.Operator.operator -> string -> (bool, string) result
 (** [is_exist operator path] Check if this path exists or not.
     
@@ -63,6 +74,17 @@ val read :
     @return data of path
 *)
 
+val reader :
+  Opendal_core.Operator.operator ->
+  string ->
+  (Opendal_core.Operator.reader, string) result
+(** [read operator path] Create a new reader which can read the whole path.
+    
+    @param operator The operator
+    @param path want to read
+    @return reader
+*)
+
 val write :
   Opendal_core.Operator.operator -> string -> bytes -> (unit, string) result
 (** [write operator path data] Write bytes into given path.
@@ -117,3 +139,41 @@ val remove_all :
     @param operator The block operator
     @param path file path
 *)
+
+module Reader : sig
+  val read : Opendal_core.Operator.reader -> bytes -> (int, string) result
+  (** [read reader buf] Read data to [buf] and return data size.*)
+
+  val seek :
+    Opendal_core.Operator.reader ->
+    int64 ->
+    Unix.seek_command ->
+    (int64, string) result
+  (** [seek reader pos mode] is a function that seeks data to the given position [pos].*)
+end
+
+module Metadata : sig
+  val is_file : Opendal_core.Operator.metadata -> bool
+  (** [is_file metadata] Returns `true` if this metadata is for a file.*)
+
+  val is_dir : Opendal_core.Operator.metadata -> bool
+  (** [is_dir metadata] Returns `true` if this metadata is for a directory.*)
+
+  val content_length : Opendal_core.Operator.metadata -> int64
+  (** [content_length metadata] Content length of this entry.*)
+
+  val content_md5 : Opendal_core.Operator.metadata -> string option
+  (** [content_md5 metadata] Content MD5 of this entry.*)
+
+  val content_type : Opendal_core.Operator.metadata -> string option
+  (** [content_type metadata] Content Type of this entry.*)
+
+  val content_disposition : Opendal_core.Operator.metadata -> string option
+  (** [content_disposition metadata] Content-Disposition of this entry*)
+
+  val etag : Opendal_core.Operator.metadata -> string option
+  (** [etag metadata] ETag of this entry.*)
+
+  val last_modified : Opendal_core.Operator.metadata -> int64 option
+  (** [last_modified metadata] Last modified of this entry.*)
+end

bindings/ocaml/src/lib.rs

@@ -22,6 +22,7 @@ use std::str::FromStr;
 use ::opendal as od;
 
 mod operator;
+mod seek_from;
 
 pub fn new_operator(
     scheme_str: String,

bindings/ocaml/src/operator.ml

@@ -2,16 +2,39 @@
 
 open! Bigarray
 
-(* file: mod.rs *)
+(* file: _type.rs *)
 
 type operator
+type reader
+type metadata
+
+(* file: metadata.rs *)
+
+external metadata_is_file: metadata -> bool  = "metadata_is_file"
+external metadata_is_dir: metadata -> bool  = "metadata_is_dir"
+external metadata_content_length: metadata -> int64  = "metadata_content_length"
+external metadata_content_md5: metadata -> string option  = "metadata_content_md5"
+external metadata_content_type: metadata -> string option  = "metadata_content_type"
+external metadata_content_disposition: metadata -> string option  = "metadata_content_disposition"
+external metadata_etag: metadata -> string option  = "metadata_etag"
+external metadata_last_modified: metadata -> int64 option  = "metadata_last_modified"
+
+(* file: mod.rs *)
+
 external operator: string -> (string * string) list -> (operator, string) Result.t  = "operator"
+external blocking_stat: operator -> string -> (metadata, string) Result.t  = "blocking_stat"
 external blocking_is_exist: operator -> string -> (bool, string) Result.t  = "blocking_is_exist"
 external blocking_create_dir: operator -> string -> (bool, string) Result.t  = "blocking_create_dir"
 external blocking_read: operator -> string -> (char array, string) Result.t  = "blocking_read"
+external blocking_reader: operator -> string -> (reader, string) Result.t  = "blocking_reader"
 external blocking_write: operator -> string -> bytes -> (unit, string) Result.t  = "blocking_write"
 external blocking_copy: operator -> string -> string -> (unit, string) Result.t  = "blocking_copy"
 external blocking_rename: operator -> string -> string -> (unit, string) Result.t  = "blocking_rename"
 external blocking_delete: operator -> string -> (unit, string) Result.t  = "blocking_delete"
 external blocking_remove: operator -> string array -> (unit, string) Result.t  = "blocking_remove"
 external blocking_remove_all: operator -> string -> (unit, string) Result.t  = "blocking_remove_all"
+
+(* file: reader.rs *)
+
+external reader_read: reader -> bytes -> (int, string) Result.t  = "reader_read"
+external reader_seek: reader -> Seek_from.seek_from -> (int64, string) Result.t  = "reader_seek"

bindings/ocaml/src/operator.mli

@@ -2,16 +2,39 @@
 
 open! Bigarray
 
-(* file: mod.rs *)
+(* file: _type.rs *)
 
 type operator
+type reader
+type metadata
+
+(* file: metadata.rs *)
+
+external metadata_is_file: metadata -> bool  = "metadata_is_file"
+external metadata_is_dir: metadata -> bool  = "metadata_is_dir"
+external metadata_content_length: metadata -> int64  = "metadata_content_length"
+external metadata_content_md5: metadata -> string option  = "metadata_content_md5"
+external metadata_content_type: metadata -> string option  = "metadata_content_type"
+external metadata_content_disposition: metadata -> string option  = "metadata_content_disposition"
+external metadata_etag: metadata -> string option  = "metadata_etag"
+external metadata_last_modified: metadata -> int64 option  = "metadata_last_modified"
+
+(* file: mod.rs *)
+
 external operator: string -> (string * string) list -> (operator, string) Result.t  = "operator"
+external blocking_stat: operator -> string -> (metadata, string) Result.t  = "blocking_stat"
 external blocking_is_exist: operator -> string -> (bool, string) Result.t  = "blocking_is_exist"
 external blocking_create_dir: operator -> string -> (bool, string) Result.t  = "blocking_create_dir"
 external blocking_read: operator -> string -> (char array, string) Result.t  = "blocking_read"
+external blocking_reader: operator -> string -> (reader, string) Result.t  = "blocking_reader"
 external blocking_write: operator -> string -> bytes -> (unit, string) Result.t  = "blocking_write"
 external blocking_copy: operator -> string -> string -> (unit, string) Result.t  = "blocking_copy"
 external blocking_rename: operator -> string -> string -> (unit, string) Result.t  = "blocking_rename"
 external blocking_delete: operator -> string -> (unit, string) Result.t  = "blocking_delete"
 external blocking_remove: operator -> string array -> (unit, string) Result.t  = "blocking_remove"
 external blocking_remove_all: operator -> string -> (unit, string) Result.t  = "blocking_remove_all"
+
+(* file: reader.rs *)
+
+external reader_read: reader -> bytes -> (int, string) Result.t  = "reader_read"
+external reader_seek: reader -> Seek_from.seek_from -> (int64, string) Result.t  = "reader_seek"

bindings/ocaml/src/operator/_type.rs

@@ -0,0 +1,32 @@
+// 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.
+
+// For ocaml-rs, the build order in the same build group is the order of the file names.
+// In order to use the type in the function in the generated ocaml file, it must be defined on the first generated file.
+use super::*;
+
+#[ocaml::sig]
+pub struct Operator(pub(crate) od::BlockingOperator);
+ocaml::custom!(Operator);
+
+#[ocaml::sig]
+pub struct Reader(pub(crate) od::BlockingReader);
+ocaml::custom!(Reader);
+
+#[ocaml::sig]
+pub struct Metadata(pub(crate) od::Metadata);
+ocaml::custom!(Metadata);

bindings/ocaml/src/operator/metadata.rs

@@ -0,0 +1,66 @@
+// 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 super::*;
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> bool ")]
+pub fn metadata_is_file(metadata: &mut Metadata) -> bool {
+    metadata.0.is_file()
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> bool ")]
+pub fn metadata_is_dir(metadata: &mut Metadata) -> bool {
+    metadata.0.is_dir()
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> int64 ")]
+pub fn metadata_content_length(metadata: &mut Metadata) -> u64 {
+    metadata.0.content_length()
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> string option ")]
+pub fn metadata_content_md5(metadata: &mut Metadata) -> Option<String> {
+    metadata.0.content_md5().map(String::from)
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> string option ")]
+pub fn metadata_content_type(metadata: &mut Metadata) -> Option<String> {
+    metadata.0.content_type().map(String::from)
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> string option ")]
+pub fn metadata_content_disposition(metadata: &mut Metadata) -> Option<String> {
+    metadata.0.content_disposition().map(String::from)
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> string option ")]
+pub fn metadata_etag(metadata: &mut Metadata) -> Option<String> {
+    metadata.0.etag().map(String::from)
+}
+
+#[ocaml::func]
+#[ocaml::sig("metadata -> int64 option ")]
+pub fn metadata_last_modified(metadata: &mut Metadata) -> Option<i64> {
+    metadata.0.last_modified().map(|t| t.timestamp())
+}

bindings/ocaml/src/operator/mod.rs

@@ -15,11 +15,12 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use super::*;
+mod _type;
+mod metadata;
+mod reader;
 
-#[ocaml::sig]
-pub struct Operator(od::BlockingOperator);
-ocaml::custom!(Operator);
+use super::*;
+use _type::*;
 
 #[ocaml::func]
 #[ocaml::sig("string -> (string * string) list -> (operator, string) Result.t ")]
@@ -31,6 +32,15 @@ pub fn operator(
     Ok(Operator(op.blocking()).into())
 }
 
+#[ocaml::func]
+#[ocaml::sig("operator -> string -> (metadata, string) Result.t ")]
+pub fn blocking_stat(
+    operator: &mut Operator,
+    path: String,
+) -> Result<ocaml::Pointer<Metadata>, String> {
+    map_res_error(operator.0.stat(path.as_str()).map(|m| Metadata(m).into()))
+}
+
 #[ocaml::func]
 #[ocaml::sig("operator -> string -> (bool, string) Result.t ")]
 pub fn blocking_is_exist(operator: &mut Operator, path: String) -> Result<bool, String> {
@@ -49,6 +59,15 @@ pub fn blocking_read(operator: &mut Operator, path: String) -> Result<Vec<u8>, S
     map_res_error(operator.0.read(path.as_str()))
 }
 
+#[ocaml::func]
+#[ocaml::sig("operator -> string -> (reader, string) Result.t ")]
+pub fn blocking_reader(
+    operator: &mut Operator,
+    path: String,
+) -> Result<ocaml::Pointer<Reader>, String> {
+    map_res_error(operator.0.reader(path.as_str())).map(|op| Reader(op).into())
+}
+
 #[ocaml::func]
 #[ocaml::sig("operator -> string -> bytes -> (unit, string) Result.t ")]
 pub fn blocking_write(