Design an in-memory file system

Medium35 minFree, no account

A tree, a path parser, and the two or three operations everyone gets subtly wrong.

The question

Implement an in-memory file system supporting mkdir, addContentToFile, readContentFromFile and ls.

Then add mv and a search by glob pattern.

fs.mkdir("/a/b/c");                  // creates every missing level
fs.addContentToFile("/a/b/c/d", "hello");
fs.readContentFromFile("/a/b/c/d");  // "hello"
fs.ls("/a/b/c");                     // ["d"]
fs.ls("/a/b/c/d");                   // ["d"]: a file lists itself

35:00Commit to an answer before you open the solution. Reading it first teaches you to recognise good answers, which is not the skill being tested.

Stuck?

0 of 3 hints taken

The worked solution

written by a person · not a grade

Score yourself

0 of 5 marked

Composite model with a shared node abstraction20
Path parsing handling root, trailing slashes and ..25
ls asymmetry between files and directories20
addContentToFile appends; mkdir creates intermediate levels20
mv guarded against moving a directory into itself15

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