Some questions about Bitmap

[Means88]

STORAGE_DIR is removed after build, however it is shared between instances. If I'm processing a and b at the same time, bitmaps added to b will be lost after a.build().

sketch-constructor/models/Sketch/Sketch.js

Line 176 in c945f56

fs.removeSync(STORAGE_DIR);

We may use os.tmpdir() if the directory is used temporarily. For developers who want to control the storage (like me 😄), they can specify the STORAGE_DIR environment and clean up manually.

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sketch-constructor/models/Bitmap/Bitmap.js

Line 80 in c945f56

const fileHash = md5File.sync(args.filePath);

The filename of a bitmap looks like a sha1 hash because it has 160bit length (40 * 0~f). But it's different from the sha1 of original image or the image inside sketch file, so I don't know how it is generated exactly (maybe it doesn't matter).

I wonder whether images from different sketch file can get conflicted (different bitmap with the same filename)? Or we can just assume that different image has a different filename?

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BitmapLayer is exported from 'bitmap/index.d.ts', which is not the same as 'bitmap/index.js'

sketch-constructor/models/Bitmap/index.d.ts

Line 15 in c945f56

export interface BitmapLayer {

It should be the declaration for 'index.js' like declare class Bitmap { ... }

I checked some of my sketch files and didn't find any layers with _class: bitmapLayer (and not found in sketch-hq/sketch-file-format). Is there anything I've missed, or just some mistakes?

[dbanksdesign]

The filename of a bitmap looks like a sha1 hash because it has 160bit length (40 * 0~f). But it's different from the sha1 of original image or the image inside sketch file, so I don't know how it is generated exactly (maybe it doesn't matter).

I spoke someone at Sketch about this. They do use sha1, but that Sketch might process the data from the file before hashing it which is why I never got a consistent hash value. They said the filename probably doesn't matter though.

You are right that 'BitmapLayer' should be 'Bitmap'. I think maybe earlier versions of Sketch called it 'bitmapLayer' or maybe we just got it wrong. I just tested it now and it should be 'bitmap' and here is the schema: https://github.com/sketch-hq/sketch-file-format/blob/master/schema/layers/bitmap.schema.yaml

[L2jLiga]

We may use os.tmpdir() if the directory is used temporarily. For developers who want to control the storage (like me 😄), they can specify the STORAGE_DIR environment and clean up manually.

Very nice suggestion :)
If we have not STORAGE_DIR environment variable specified -> use temporary directory, like it 👍