Create a WorkspaceRawFile workspace type and alter LoadRaw to use it.

[Nick Draper]

At the moment the first workspace created from a LoadRaw is an exact memory copy of the data in the file. The idea here is to save memory by only creating a workspace type facade that loads the data from the file as it is required.

Things to consider

• Instrument and spectra-detector table etc - this associated information should be loaded in full as normal
• Loading data on demand - It will probably be necessary to load the data in 'chunks' of n spectra
• What if an algorithm tries to modify this workspace? - This workspacetype should be read only. If someone tries to modify it it should copy all of it's data into a normal Workspace2D (or ManagedWorkspace2D) to continue.

[Roman Tolchenov]

(In [1472]) LoadRaw version 2 is added. Small modifications to MemoryManager. re #190

[Roman Tolchenov]

(In [1474]) Test corrected. re #190

[Nick Draper]

Suggested steps to start this

1. Learn and understand how ManagedWorkspace2D and the ManagedDataBlock classes work.
2. Create copied classes for ManagedWorkspace2D and ManagedDataBlock that use a RAW file as their data storage file. For now just disallow/ignore any operations that would modify the data
3. Modify the existing ManagedWorkspace2D classes to seperate the file operations from the rest of the code. These operations should be called through virtual methods that can be overwritten.
4. Create an ManagedRawWorkspace2D class that inherits from ManagedWrokspace2D, and provides alternate implementations for the virtual methods that use the RAW file rather than the flat file.
5. Intercept calls that would alter a datablock and change that block to use flat file storage. Alter the datablock loading to handle this.

[Roman Tolchenov]

(In [1507]) Added ManagedRawFileWorkspace2D workspace which does not load the data into memory until it is needed. LoadRaw2 and MantidPlot are modified to use it. re #190

[Roman Tolchenov]

(In [1513]) Changed LoadRaw2 to load instrument into ManagedRawFileWorkspace2D. Added LoadRaw2Test and ManagedRawFileWorkspace2DTest. re #190

[Roman Tolchenov]

(In [1514]) fixed ManagedRawFileWorkspace2DTest. re #190

[Roman Tolchenov]

(In [1515]) re #190

[Roman Tolchenov]

(In [1516]) re #190

[Roman Tolchenov]

(In [1517]) re #190

[Roman Tolchenov]

(In [1536]) Improved thread safety for ManagedRawFileWorkspace2D, re #190. Improved the look of MantidMatrix, re #272

[Stuart Campbell]

This ticket has been transferred to github issue ​1038