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Block API

block.get

Get a raw IPFS block.

ipfs.block.get(cid, [options], [callback])

cid is a cid which can be passed as:

  • Buffer, the raw Buffer of the cid
  • CID, a CID instance
  • String, the base58 encoded version of the multihash

callback must follow function (err, block) {} signature, where err is an error if the operation was not successful and block is a Block type object, containing both the data and the hash of the block.

If no callback is passed, a promise is returned.

Example:

ipfs.block.get(cid, function (err, block) {
  if (err) {
    throw err
  }
  block.key((err, key) => {
    if (err) {
      throw err
    }
    console.log(key, block.data)
  })
})

A great source of examples can be found in the tests for this API.

block.put

Stores input as an IPFS block.

ipfs.block.put(block, [options], [callback])

Where block can be:

  • Buffer - the raw bytes of the Block
  • Block instance

and options is an Object that can contain the following properties:

  • cid - a cid which can be passed as:
    • Buffer, the raw Buffer of the cid
    • CID, a CID instance
    • String, the base58 encoded version of the multihash
  • format
  • mhtype
  • mhlen
  • version

if no options are passed, it defaults to { format: 'dag-pb', mhtype: 'sha2-256', version: 0 }

Note: If you pass a Block instance as the block parameter, you don't need to pass options, as the block instance will carry the CID value as a property.

callback has the signature function (err, block) {}, where err is an error if the operation was not successful and block is a Block type object, containing both the data and the hash of the block.

If no callback is passed, a promise is returned.

Example:

// Defaults
const buf = new Buffer('a serialized object')

ipfs.block.put(buf, (err, block) => {
  if (err) { throw err }
  // Block has been stored

  console.log(block.data.toString())
  // Logs:
  // a serialized object
  console.log(block.cid.toBaseEncodedString())
  // Logs:
  // the CID of the object
})

// With custom format and hashtype through CID
const CID = require('cids')
const buf = new Buffer('another serialized object')
const cid = new CID(1, 'dag-pb', multihash)

ipfs.block.put(blob, cid, (err, block) => {
  if (err) { throw err }
  // Block has been stored

  console.log(block.data.toString())
  // Logs:
  // a serialized object
  console.log(block.cid.toBaseEncodedString())
  // Logs:
  // the CID of the object
})

A great source of examples can be found in the tests for this API.

block.stat

Print information of a raw IPFS block.

ipfs.block.stat(cid, [callback])

cid is a cid which can be passed as:

  • Buffer, the raw Buffer of the multihash (or of and encoded version)
  • String, the toString version of the multihash (or of an encoded version)
  • CID, a CID instance

callback must follow the signature function (err, stats) {}, where err is an error if the operation was not successful and stats is an object with the format:`

{
  key: 'QmPTkMuuL6PD8L2SwTwbcs1NPg14U8mRzerB1ZrrBrkSDD',
  size: 10
}

If no callback is passed, a promise is returned.

Example:

const multihashStr = 'QmQULBtTjNcMwMr4VMNknnVv3RpytrLSdgpvMcTnfNhrBJ'
const cid = new CID(multihashStr)

ipfs.block.stat(cid, (err, stats) => {
  if (err) {
    throw err
  }
  console.log(stats)
  // Logs:
  // {
  //   key: QmQULBtTjNcMwMr4VMNknnVv3RpytrLSdgpvMcTnfNhrBJ,
  /    size: 3739
  // }
})

A great source of examples can be found in the tests for this API.

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