alt Hacker NewsWhat is the point of using a generic compression algorithm in a file format? Does this actually get you much over turning on filesystem and transport compression, which can transparently swap the generic algorithm (e.g. my files are already all zstd compressed. HTTP can already negotiate brotli or zstd)? If it's not tuned to the application, it seems like it's better to leave it uncompressed and let the user decide what they want (e.g. people noting tradeoffs with bro vs zstd; let the person who has to live with the tradeoff decide it, not the original file author).
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Few people enable file system compression, and even if they do it's usually with fast algorithms like lz4 or zstd -1. When authoring a document you have very different tradeoffs and can afford the cost of high compression levels of zstd or brotli.
- inside the file, the compressor can be varied according to the file content. For example, images can use jpeg, but that isn’t useful for compressing text
- when jumping from page to page, you won’t have to decompress the entire file
Well, if sanity had prevailed, we would have likely stuck to .ps.gz (or you favourite compression format), instead of ending up with PDF.
Though we might still want to restrict the subset of PostScript that we allow. The full language might be a bit too general to take from untrusted third parties.