wekan/packages/wekan-cfs-temp-store/internal.api.md

Public and Private API

API documentation automatically generated by docmeteor.

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File: "tempStore.js" Where: {server}

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##Temporary Storage

Temporary storage is used for chunked uploads until all chunks are received and all copies have been made or given up. In some cases, the original file is stored only in temporary storage (for example, if all copies do some manipulation in beforeSave). This is why we use the temporary file as the basis for each saved copy, and then remove it after all copies are saved.

Every chunk is saved as an individual temporary file. This is safer than attempting to write multiple incoming chunks to different positions in a single temporary file, which can lead to write conflicts.

Using temp files also allows us to easily resume uploads, even if the server restarts, and to keep the working memory clear.

The FS.TempStore emits events that others are able to listen to

fs.TempStore {object}  _Server

This property TempStore is defined in FS it's an event emitter*

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### <a name="FS.TempStore.Storage"></a>*fsTempstore*.Storage {StorageAdapter}&nbsp;&nbsp;<sub><i>Server</i></sub> ###

*This property is private*
*This property __Storage__ is defined in `FS.TempStore`*

This property is set to either `FS.Store.FileSystem` or `FS.Store.GridFS`

__When and why:__
We normally default to `cfs-filesystem` unless its not installed. *(we default to gridfs if installed)*
But if `cfs-gridfs` and `cfs-worker` is installed we default to `cfs-gridfs`

If `cfs-gridfs` and `cfs-filesystem` is not installed we log a warning.
the user can set `FS.TempStore.Storage` them selfs eg.:

js // Its important to set internal: true this lets the SA know that we // are using this internally and it will give us direct SA api FS.TempStore.Storage = new FS.Store.GridFS('_tempstore', { internal: true });

> Note: This is considered as `advanced` use, its not a common pattern.

> ```FS.TempStore.Storage = null;``` [tempStore.js:54](tempStore.js#L54)



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We will not mount a storage adapter until needed. This allows us to check for the
existance of FS.FileWorker, which is loaded after this package because it
depends on this package.

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XXX: TODO
FS.TempStore.on('stored', function(fileObj, chunkCount, result) {
This should work if we pass on result from the SA on stored event...
fileObj.update({ $set: { chunkSum: 1, chunkCount: chunkCount, size: result.size } });
});
Stream implementation
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### <a name="_chunkPath"></a>_chunkPath([n])&nbsp;&nbsp;<sub><i>Server</i></sub> ###

*This method is private*

__Arguments__

* __n__ *{Number}*  (Optional)

 Chunk number


__Returns__  *{String}*
Chunk naming convention


> ```_chunkPath = function(n) { ...``` [tempStore.js:104](tempStore.js#L104)


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### <a name="_fileReference"></a>_fileReference(fileObj, chunk)&nbsp;&nbsp;<sub><i>Server</i></sub> ###

*This method is private*

__Arguments__

* __fileObj__ *{[FS.File](#FS.File)}*  
* __chunk__ *{Number}*  

__Returns__  *{String}*
Generated SA specific fileKey for the chunk


Note: Calling function should call mountStorage() first, and
make sure that fileObj is mounted.

> ```_fileReference = function(fileObj, chunk, existing) { ...``` [tempStore.js:118](tempStore.js#L118)


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### <a name="FS.TempStore.exists"></a>*fsTempstore*.exists(File)&nbsp;&nbsp;<sub><i>Server</i></sub> ###

*This method __exists__ is defined in `FS.TempStore`*

__Arguments__

* __File__ *{[FS.File](#FS.File)}*  

 object


__Returns__  *{Boolean}*
Is this file, or parts of it, currently stored in the TempStore


> ```FS.TempStore.exists = function(fileObj) { ...``` [tempStore.js:145](tempStore.js#L145)


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### <a name="FS.TempStore.listParts"></a>*fsTempstore*.listParts(fileObj)&nbsp;&nbsp;<sub><i>Server</i></sub> ###

*This method __listParts__ is defined in `FS.TempStore`*

__Arguments__

* __fileObj__ *{[FS.File](#FS.File)}*  

__Returns__  *{Object}*
of parts already stored

__TODO__

• This is not yet implemented, milestone 1.1.0

  FS.TempStore.listParts = function(fileObj) { ...``` tempStore.js:156

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fsTempstore.removeFile(fileObj)  _Server

This method removeFile is defined in FS.TempStore

Arguments

• fileObj {FS.File}
  

This function removes the file from tempstorage - it cares not if file is already removed or not found, goal is reached anyway.

FS.TempStore.removeFile = function(fileObj) { ... tempStore.js:169

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fsTempstore.createWriteStream(fileObj, [options])  _Server

This method createWriteStream is defined in FS.TempStore

Arguments

• fileObj {FS.File}
  

File to store in temporary storage

• options {Number | String} (Optional)

Returns {Stream} Writeable stream

options of different types mean differnt things: undefined We store the file in one part (Normal server-side api usage)* Number the number is the part number total (multipart uploads will use this api)* String the string is the name of the store that wants to store file data (stores that want to sync their data to the rest of the files stores will use this)*

Note: fileObj must be mounted on a FS.Collection, it makes no sense to store otherwise

FS.TempStore.createWriteStream = function(fileObj, options) { ... tempStore.js:217

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fsTempstore.createReadStream(fileObj)  _Server

This method createReadStream is defined in FS.TempStore

Arguments

• fileObj {FS.File}
  

The file to read

Returns {Stream} Returns readable stream

FS.TempStore.createReadStream = function(fileObj) { ... tempStore.js:313