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| -rw-r--r-- | doc/HACKING/design/01b-collections.md | 45 |
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diff --git a/doc/HACKING/design/01b-collections.md b/doc/HACKING/design/01b-collections.md deleted file mode 100644 index ed6fdc9071..0000000000 --- a/doc/HACKING/design/01b-collections.md +++ /dev/null @@ -1,45 +0,0 @@ - -## Collections in tor - -### Smartlists: Neither lists, nor especially smart. - -For historical reasons, we call our dynamic-allocated array type -`smartlist_t`. It can grow or shrink as elements are added and removed. - -All smartlists hold an array of `void *`. Whenever you expose a smartlist -in an API you *must* document which types its pointers actually hold. - -<!-- It would be neat to fix that, wouldn't it? -NM --> - -Smartlists are created empty with `smartlist_new()` and freed with -`smartlist_free()`. See the `containers.h` module documentation for more -information; there are many convenience functions for commonly needed -operations. - -<!-- TODO: WRITE more about what you can do with smartlists. --> - -### Digest maps, string maps, and more. - -Tor makes frequent use of maps from 160-bit digests, 256-bit digests, -or nul-terminated strings to `void *`. These types are `digestmap_t`, -`digest256map_t`, and `strmap_t` respectively. See the containers.h -module documentation for more information. - -### Intrusive lists and hashtables - -For performance-sensitive cases, we sometimes want to use "intrusive" -collections: ones where the bookkeeping pointers are stuck inside the -structures that belong to the collection. If you've used the -BSD-style sys/queue.h macros, you'll be familiar with these. - -Unfortunately, the `sys/queue.h` macros vary significantly between the -platforms that have them, so we provide our own variants in -`src/ext/tor_queue.h`. - -We also provide an intrusive hashtable implementation in `src/ext/ht.h`. -When you're using it, you'll need to define your own hash -functions. If attacker-induced collisions are a worry here, use the -cryptographic siphash24g function to extract hashes. - -<!-- TODO: WRITE about bloom filters, namemaps, bit-arrays, order functions. ---> |