On Thursday, 5 April 2012 at 15:00:04 UTC, BLM wrote:
Recently I've been working on some projects that involve parsing binary files. I've mainly been using std.file.read() to get the whole file as a huge array and then extracting slices. I had initially assumed that the GC would free any chunks of the array that didn't end up being referenced by these slices, but after reading some more, it looks like the whole array is kept in memory even if only a few elements are actually referenced. Is this actually the case? If so, might the language be extended to handle this situation?
The GC can't really know which parts of the array you're using. For example, your only reference to the array might be a pointer, and you might be traversing the array in either direction, only keeping count of the remaining bytes until the array boundary.
Consider .dup-ing the slices you're going to need, or using std.mmfile to map the file into memory - in that case, the OS won't load the unnecessary parts of the file into memory in the first place.
