Documentation
¶
Overview ¶
Package mod provides DAG modification utilities to, for example, insert additional nodes in a unixfs DAG or truncate them.
Index ¶
- Variables
- func FileSize(n ipld.Node) (uint64, error)
- type DagModifier
- func (dm *DagModifier) CtxReadFull(ctx context.Context, b []byte) (int, error)
- func (dm *DagModifier) GetCtx() context.Context
- func (dm *DagModifier) GetDserv() ipld.DAGService
- func (dm *DagModifier) GetNode() (ipld.Node, error)
- func (dm *DagModifier) HasChanges() bool
- func (dm *DagModifier) Read(b []byte) (int, error)
- func (dm *DagModifier) Seek(offset int64, whence int) (int64, error)
- func (dm *DagModifier) Size() (int64, error)
- func (dm *DagModifier) Sync() error
- func (dm *DagModifier) Truncate(size int64) error
- func (dm *DagModifier) Write(b []byte) (int, error)
- func (dm *DagModifier) WriteAt(b []byte, offset int64) (int, error)
- type MetaDagModifier
Constants ¶
This section is empty.
Variables ¶
var ( ErrSeekFail = errors.New("failed to seek properly") ErrUnrecognizedWhence = errors.New("unrecognized whence") ErrNotUnixfs = errors.New("dagmodifier only supports unixfs nodes (proto or raw)") )
Common errors
Functions ¶
Types ¶
type DagModifier ¶
type DagModifier struct {
Prefix cid.Prefix
RawLeaves bool
BalancedFormat bool
Maxlinks int
// contains filtered or unexported fields
}
DagModifier is the only struct licensed and able to correctly perform surgery on a DAG 'file' Dear god, please rename this to something more pleasant
func NewDagModifier ¶
func NewDagModifier(ctx context.Context, from ipld.Node, serv ipld.DAGService, spl chunker.SplitterGen) (*DagModifier, error)
NewDagModifier returns a new DagModifier, the Cid prefix for newly created nodes will be inhered from the passed in node. If the Cid version if not 0 raw leaves will also be enabled. The Prefix and RawLeaves options can be overridden by changing them after the call.
func NewDagModifierBalanced ¶ added in v0.4.8
func NewDagModifierBalanced(ctx context.Context, from ipld.Node, serv ipld.DAGService, spl chunker.SplitterGen, ml int, noMeta bool) (*DagModifier, error)
func (*DagModifier) CtxReadFull ¶
CtxReadFull reads data from this dag starting at the current offset
func (*DagModifier) GetCtx ¶ added in v0.4.8
func (dm *DagModifier) GetCtx() context.Context
func (*DagModifier) GetDserv ¶ added in v0.4.8
func (dm *DagModifier) GetDserv() ipld.DAGService
func (*DagModifier) GetNode ¶
func (dm *DagModifier) GetNode() (ipld.Node, error)
GetNode gets the modified DAG Node
func (*DagModifier) HasChanges ¶
func (dm *DagModifier) HasChanges() bool
HasChanges returned whether or not there are unflushed changes to this dag
func (*DagModifier) Read ¶
func (dm *DagModifier) Read(b []byte) (int, error)
Read data from this dag starting at the current offset
func (*DagModifier) Seek ¶
func (dm *DagModifier) Seek(offset int64, whence int) (int64, error)
Seek modifies the offset according to whence. See unixfs/io for valid whence values.
func (*DagModifier) Size ¶
func (dm *DagModifier) Size() (int64, error)
Size returns the Filesize of the node
func (*DagModifier) Sync ¶
func (dm *DagModifier) Sync() error
Sync writes changes to this dag to disk
func (*DagModifier) Truncate ¶
func (dm *DagModifier) Truncate(size int64) error
Truncate truncates the current Node to 'size' and replaces it with the new one.
type MetaDagModifier ¶ added in v0.4.9
type MetaDagModifier struct {
*DagModifier
Overwrite bool
// contains filtered or unexported fields
}
func NewMetaDagModifierBalanced ¶ added in v0.4.9
func NewMetaDagModifierBalanced(mod *DagModifier, db *help.DagBuilderHelper, overwrite bool) *MetaDagModifier
func (*MetaDagModifier) AddMetadata ¶ added in v0.4.9
AddMetadata puts the given `metadata` items to the given `root` that is the top node of a BTFS file DAG and returns a new root for the BTFS file DAG.
There are three scenarios possible: Scenario #1. No existing metadata for the `root`. So this scenario is
to create a new metadata sub-DAG.
Scenario #2. There are existing keys for the given `metadata` items.
Then this is to update the metadata sub-DAG with the given items.
Scenario #3. There are no pre-existing metadata items for the given `metadata` items.
Then this scenario is to append given items to the metadata sub-DAG.
TODO: trickle format Preconditions include that first the given `metadata` is in compact JSON format. Note that the given `metadata` should be added to the first element of the metadata list.
func (*MetaDagModifier) GetDb ¶ added in v0.4.9
func (mdm *MetaDagModifier) GetDb() *help.DagBuilderHelper
func (*MetaDagModifier) RemoveMetadata ¶ added in v0.4.9
RemoveMetadata first truncate the metadata dag from the given `root`, update the metadata map with the given `metadata`, then calls meta-dag builder to create a metadata subDag and attach the metadata dag to a new root with the given `dataroot` being a child of the new root. The preconditions include that first the given `metadata` is a string with keys separated by commas, second`mdm.curNode` has the root of the metadata sub-DAG.
Source Files