Add config to explicitly specify the dll version (Saghen#36)

This adds a new `fuzzy.prebuiltBinaries` config table which allows:

1. Enabling or disabling the dll downloader
2. Explicitly specifying the version to download

This is useful if I want to track master without needing to run
`cargo build --release`.

README.md

@@ -164,6 +164,17 @@ For LazyVim/distro users, you can disable nvim-cmp via:
     max_items = 200,
     -- controls which sorts to use and in which order, these three are currently the only allowed options
     sorts = { 'label', 'kind', 'score' },
+
+    prebuiltBinaries = {
+      -- Whether or not to automatically download a prebuilt binary from github. If this is set to `false`
+      -- you will need to manually build the fuzzy binary dependencies by running `cargo build --release`
+      download = true,
+      -- When downloading a prebuilt binary force the downloader to resolve this version. If this is uset
+      -- then the downloader will attempt to infer the version from the checked out git tag (if any).
+      --
+      -- Beware that if the FFI ABI changes while tracking main then this may result in blink breaking.
+      forceVersion = nil,
+    },
   },
 
   sources = {

lua/blink/cmp/config.lua

@@ -61,11 +61,16 @@
 --- @field enabled boolean
 --- @field priority number
 
+--- @class blink.cmp.PrebuiltBinariesConfig
+--- @field download boolean
+--- @field forceVersion string | nil
+
 --- @class blink.cmp.FuzzyConfig
 --- @field use_frecency boolean
 --- @field use_proximity boolean
 --- @field max_items number
 --- @field sorts ("label" | "kind" | "score")[]
+--- @field prebuiltBinaries blink.cmp.PrebuiltBinariesConfig
 
 --- @class blink.cmp.WindowConfig
 --- @field autocomplete blink.cmp.AutocompleteConfig
@@ -201,6 +206,16 @@ local config = {
     max_items = 200,
     -- controls which sorts to use and in which order, these three are currently the only allowed options
     sorts = { 'label', 'kind', 'score' },
+    prebuiltBinaries = {
+      -- Whether or not to automatically download a prebuilt binary from github. If this is set to `false`
+      -- you will need to manually build the fuzzy binary dependencies by running `cargo build --release`
+      download = true,
+      -- When downloading a prebuilt binary force the downloader to resolve this version. If this is uset
+      -- then the downloader will attempt to infer the version from the checked out git tag (if any).
+      --
+      -- Beware that if the FFI ABI changes while tracking main then this may result in blink breaking.
+      forceVersion = nil,
+    },
   },
 
   sources = {

lua/blink/cmp/fuzzy/download.lua

@@ -1,3 +1,5 @@
+local download_config = require('blink.cmp.config').fuzzy.prebuiltBinaries
+
 local download = {}
 
 --- @return string
@@ -17,28 +19,34 @@ function download.ensure_downloaded(callback)
     vim.schedule(function() callback(err) end)
   end
 
+  if not download_config.download then return cb() end
+
   download.get_git_tag(function(git_version_err, git_version)
     if git_version_err then return cb(git_version_err) end
 
     download.get_downloaded_version(function(version_err, version)
       download.is_downloaded(function(downloaded)
+        local target_version = download_config.forceVersion or git_version
+
         -- not built locally, not a git tag, error
-        if not downloaded and not git_version then
+        if not downloaded and not target_version then
           return cb(
-            "Can't download from github due to not being on a git tag but found no built version of the library. Either run cargo build --release via your package manager or switch to a git tag. See the README for more info."
+            "Can't download from github due to not being on a git tag and no native_download.version set, but found no built version of the library. "
+              .. 'Either run `cargo build --release` via your package manager, switch to a git tag, or set `native_download.version` in config. '
+              .. 'See the README for more info.'
           )
         end
         -- built locally, ignore
         if downloaded and (version_err or version == nil) then return cb() end
         -- already downloaded and the correct version
-        if version == git_version and downloaded then return cb() end
+        if version == target_version and downloaded then return cb() end
         -- unknown state
-        if not git_version then return cb('Unknown error while getting pre-built binary. Consider re-installing') end
+        if not target_version then return cb('Unknown error while getting pre-built binary. Consider re-installing') end
 
         -- download from github and set version
-        download.from_github(git_version, function(download_err)
+        download.from_github(target_version, function(download_err)
           if download_err then return cb(download_err) end
-          download.set_downloaded_version(git_version, function(set_err)
+          download.set_downloaded_version(target_version, function(set_err)
             if set_err then return cb(set_err) end
             cb()
           end)