Trait opendal::raw::Accessor

pub trait Accessor: Send + Sync + Debug + Unpin + 'static {
    type Reader: Read;
    type BlockingReader: BlockingRead;
    type Writer: Write;
    type BlockingWriter: BlockingWrite;
    type Pager: Page;
    type BlockingPager: BlockingPage;

    // Required method
    fn info(&self) -> AccessorInfo;

    // Provided methods
    fn create<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpCreate
    ) -> Pin<Box<dyn Future<Output = Result<RpCreate>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn read<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpRead
    ) -> Pin<Box<dyn Future<Output = Result<(RpRead, Self::Reader)>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn write<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpWrite
    ) -> Pin<Box<dyn Future<Output = Result<(RpWrite, Self::Writer)>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn stat<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpStat
    ) -> Pin<Box<dyn Future<Output = Result<RpStat>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn delete<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpDelete
    ) -> Pin<Box<dyn Future<Output = Result<RpDelete>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn list<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpList
    ) -> Pin<Box<dyn Future<Output = Result<(RpList, Self::Pager)>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn scan<'life0, 'life1, 'async_trait>(
        &'life0 self,
        path: &'life1 str,
        args: OpScan
    ) -> Pin<Box<dyn Future<Output = Result<(RpScan, Self::Pager)>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn presign(&self, path: &str, args: OpPresign) -> Result<RpPresign> { ... }
    fn batch<'life0, 'async_trait>(
        &'life0 self,
        args: OpBatch
    ) -> Pin<Box<dyn Future<Output = Result<RpBatch>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait { ... }
    fn blocking_create(&self, path: &str, args: OpCreate) -> Result<RpCreate> { ... }
    fn blocking_read(
        &self,
        path: &str,
        args: OpRead
    ) -> Result<(RpRead, Self::BlockingReader)> { ... }
    fn blocking_write(
        &self,
        path: &str,
        args: OpWrite
    ) -> Result<(RpWrite, Self::BlockingWriter)> { ... }
    fn blocking_stat(&self, path: &str, args: OpStat) -> Result<RpStat> { ... }
    fn blocking_delete(&self, path: &str, args: OpDelete) -> Result<RpDelete> { ... }
    fn blocking_list(
        &self,
        path: &str,
        args: OpList
    ) -> Result<(RpList, Self::BlockingPager)> { ... }
    fn blocking_scan(
        &self,
        path: &str,
        args: OpScan
    ) -> Result<(RpScan, Self::BlockingPager)> { ... }
}

Underlying trait of all backends for implementors.

Note

Visit internals for more tutorials.

Operations

• Path in args will all be normalized into the same style, services should handle them based on services’ requirement.
  • Path that ends with / means it’s Dir, otherwise, it’s File.
  • Root dir is /
  • Path will never be empty.
• Operations without capability requirement like metadata, create are basic operations.
  • All services must implement them.
  • Use unimplemented!() if not implemented or can’t implement.
• Operations with capability requirement like presign are optional operations.
  • Services can implement them based on services capabilities.
  • The default implementation should return ErrorKind::Unsupported.

Required Associated Types

type Reader: Read

Reader is the associated reader the could return in read operation.

type BlockingReader: BlockingRead

BlockingReader is the associated reader that could return in blocking_read operation.

type Writer: Write

Reader is the associated writer the could return in write operation.

type BlockingWriter: BlockingWrite

BlockingWriter is the associated writer the could return in blocking_write operation.

type Pager: Page

Pager is the associated page that return in list or scan operation.

type BlockingPager: BlockingPage

BlockingPager is the associated pager that could return in blocking_list or scan operation.

Required Methods

fn info(&self) -> AccessorInfo

Invoke the info operation to get metadata of accessor.

Notes

This function is required to be implemented.

By returning AccessorInfo, underlying services can declare some useful information about it self.

• scheme: declare the scheme of backend.
• capabilities: declare the capabilities of current backend.
• hints: declare the hints of current backend

Provided Methods

fn create<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpCreate ) -> Pin<Box<dyn Future<Output = Result<RpCreate>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the create operation on the specified path

Require AccessorCapability::Write

Behavior

• Input path MUST match with EntryMode, DON’T NEED to check mode.
• Create on existing dir SHOULD succeed.
• Create on existing file SHOULD overwrite and truncate.

fn read<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpRead ) -> Pin<Box<dyn Future<Output = Result<(RpRead, Self::Reader)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the read operation on the specified path, returns a Reader if operate successful.

Require AccessorCapability::Read

Behavior

• Input path MUST be file path, DON’T NEED to check mode.
• The returning content length may be smaller than the range specified.

fn write<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpWrite ) -> Pin<Box<dyn Future<Output = Result<(RpWrite, Self::Writer)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the write operation on the specified path, returns a written size if operate successful.

Require AccessorCapability::Write

Behavior

• Input path MUST be file path, DON’T NEED to check mode.

fn stat<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpStat ) -> Pin<Box<dyn Future<Output = Result<RpStat>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the stat operation on the specified path.

Require AccessorCapability::Read

Behavior

• stat empty path means stat backend’s root path.
• stat a path endswith “/” means stating a dir.
• mode and content_length must be set.

fn delete<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpDelete ) -> Pin<Box<dyn Future<Output = Result<RpDelete>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the delete operation on the specified path.

Require AccessorCapability::Write

Behavior

• delete is an idempotent operation, it’s safe to call Delete on the same path multiple times.
• delete SHOULD return Ok(()) if the path is deleted successfully or not exist.

fn list<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpList ) -> Pin<Box<dyn Future<Output = Result<(RpList, Self::Pager)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the list operation on the specified path.

Require AccessorCapability::List

Behavior

• Input path MUST be dir path, DON’T NEED to check mode.
• List non-exist dir should return Empty.

fn scan<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpScan ) -> Pin<Box<dyn Future<Output = Result<(RpScan, Self::Pager)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Invoke the scan operation on the specified path.

Require AccessorCapability::Scan

fn presign(&self, path: &str, args: OpPresign) -> Result<RpPresign>

Invoke the presign operation on the specified path.

Require AccessorCapability::Presign

Behavior

• This API is optional, return std::io::ErrorKind::Unsupported if not supported.

fn batch<'life0, 'async_trait>( &'life0 self, args: OpBatch ) -> Pin<Box<dyn Future<Output = Result<RpBatch>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait,

Invoke the batch operations.

fn blocking_create(&self, path: &str, args: OpCreate) -> Result<RpCreate>

Invoke the blocking_create operation on the specified path.

This operation is the blocking version of Accessor::create

Require AccessorCapability::Write and AccessorCapability::Blocking

fn blocking_read( &self, path: &str, args: OpRead ) -> Result<(RpRead, Self::BlockingReader)>

Invoke the blocking_read operation on the specified path.

This operation is the blocking version of Accessor::read

Require AccessorCapability::Read and AccessorCapability::Blocking

fn blocking_write( &self, path: &str, args: OpWrite ) -> Result<(RpWrite, Self::BlockingWriter)>

Invoke the blocking_write operation on the specified path.

This operation is the blocking version of Accessor::write

Require AccessorCapability::Write and AccessorCapability::Blocking

fn blocking_stat(&self, path: &str, args: OpStat) -> Result<RpStat>

Invoke the blocking_stat operation on the specified path.

This operation is the blocking version of Accessor::stat

Require AccessorCapability::Read and AccessorCapability::Blocking

fn blocking_delete(&self, path: &str, args: OpDelete) -> Result<RpDelete>

Invoke the blocking_delete operation on the specified path.

This operation is the blocking version of Accessor::delete

Require AccessorCapability::Write and AccessorCapability::Blocking

fn blocking_list( &self, path: &str, args: OpList ) -> Result<(RpList, Self::BlockingPager)>

Invoke the blocking_list operation on the specified path.

This operation is the blocking version of Accessor::list

Require AccessorCapability::List and AccessorCapability::Blocking

Behavior

• List non-exist dir should return Empty.

fn blocking_scan( &self, path: &str, args: OpScan ) -> Result<(RpScan, Self::BlockingPager)>

Invoke the blocking_scan operation on the specified path.

Require AccessorCapability::Scan and AccessorCapability::Blocking

Implementations on Foreign Types

impl Accessor for ()

Dummy implementation of accessor.

type Reader = ()

type BlockingReader = ()

type Writer = ()

type BlockingWriter = ()

type Pager = ()

type BlockingPager = ()

fn info(&self) -> AccessorInfo

impl<T: Accessor + ?Sized> Accessor for Arc<T>

All functions in Accessor only requires &self, so it’s safe to implement Accessor for Arc<dyn Accessor>.

type Reader = <T as Accessor>::Reader

type BlockingReader = <T as Accessor>::BlockingReader

type Writer = <T as Accessor>::Writer

type BlockingWriter = <T as Accessor>::BlockingWriter

type Pager = <T as Accessor>::Pager

type BlockingPager = <T as Accessor>::BlockingPager

fn info(&self) -> AccessorInfo

fn create<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpCreate ) -> Pin<Box<dyn Future<Output = Result<RpCreate>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn read<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpRead ) -> Pin<Box<dyn Future<Output = Result<(RpRead, Self::Reader)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn write<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpWrite ) -> Pin<Box<dyn Future<Output = Result<(RpWrite, Self::Writer)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn stat<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpStat ) -> Pin<Box<dyn Future<Output = Result<RpStat>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn delete<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpDelete ) -> Pin<Box<dyn Future<Output = Result<RpDelete>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn list<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpList ) -> Pin<Box<dyn Future<Output = Result<(RpList, Self::Pager)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn scan<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 str, args: OpScan ) -> Pin<Box<dyn Future<Output = Result<(RpScan, Self::Pager)>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

fn batch<'life0, 'async_trait>( &'life0 self, args: OpBatch ) -> Pin<Box<dyn Future<Output = Result<RpBatch>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait,

fn presign(&self, path: &str, args: OpPresign) -> Result<RpPresign>

fn blocking_create(&self, path: &str, args: OpCreate) -> Result<RpCreate>

fn blocking_read( &self, path: &str, args: OpRead ) -> Result<(RpRead, Self::BlockingReader)>

fn blocking_write( &self, path: &str, args: OpWrite ) -> Result<(RpWrite, Self::BlockingWriter)>

fn blocking_stat(&self, path: &str, args: OpStat) -> Result<RpStat>

fn blocking_delete(&self, path: &str, args: OpDelete) -> Result<RpDelete>

fn blocking_list( &self, path: &str, args: OpList ) -> Result<(RpList, Self::BlockingPager)>

fn blocking_scan( &self, path: &str, args: OpScan ) -> Result<(RpScan, Self::BlockingPager)>

Implementors

impl<L: LayeredAccessor> Accessor for L

type Reader = <L as LayeredAccessor>::Reader

type BlockingReader = <L as LayeredAccessor>::BlockingReader

type Writer = <L as LayeredAccessor>::Writer

type BlockingWriter = <L as LayeredAccessor>::BlockingWriter

type Pager = <L as LayeredAccessor>::Pager

type BlockingPager = <L as LayeredAccessor>::BlockingPager

impl<S: Adapter> Accessor for Backend<S>

type Reader = Cursor

type BlockingReader = Cursor

type Writer = KvWriter<S>

type BlockingWriter = KvWriter<S>

type Pager = KvPager

type BlockingPager = KvPager