feat(fuzzy): make frecency database path configurable

This adds a new frecency config table with options to enable it, set the
database path, and tweak locking.

It also deprecates the old boolean flags `fuzzy.use_frecency` and
`fuzzy.use_unsafe_no_lock`, showing a heads-up notice when used.

```lua
fuzzy = {
  -- OLD
  use_frecency = true,
  use_unsafe_no_lock = false,

  -- NEW
  frecency = {
    enabled = true,
    unsafe_no_lock = false,
  }
}
```

If an old frecency database directory exists, it will be automatically
migrated to the new configurable location, no manual steps needed.

Closes #2006

Author: soifou

doc/configuration/reference.md

@@ -406,16 +406,22 @@ fuzzy = {
 
   -- Frecency tracks the most recently/frequently used items and boosts the score of the item
   -- Note, this does not apply when using the Lua implementation.
-  use_frecency = true,
+  frecency = {
+    -- Whether to enable the frecency feature
+    enabled = true,
+    -- Location of the frecency database
+    path = vim.fn.stdpath('state') .. '/blink/cmp/fuzzy.db',
+    -- UNSAFE!! When enabled, disables the lock and fsync when writing to the frecency database. 
+    -- This should only be used on unsupported platforms (i.e. alpine termux)
+    unsafe_no_lock = false,
+  },
+  use_frecency = true, -- deprecated alias for frecency.enabled, will be removed in v2.0
+  use_unsafe_no_lock = false, -- deprecated alias for frecency.unsafe_no_lock, will be removed in v2.0
 
   -- Proximity bonus boosts the score of items matching nearby words
   -- Note, this does not apply when using the Lua implementation.
   use_proximity = true,
 
-  -- UNSAFE!! When enabled, disables the lock and fsync when writing to the frecency database. This should only be used on unsupported platforms (i.e. alpine termux)
-  -- Note, this does not apply when using the Lua implementation.
-  use_unsafe_no_lock = false,
-
   -- Controls which sorts to use and in which order, falling back to the next sort if the first one returns nil
   -- You may pass a function instead of a string to customize the sorting
   sorts = {

lua/blink/cmp/config/fuzzy.lua

@@ -1,12 +1,18 @@
 --- @class (exact) blink.cmp.FuzzyConfig
 --- @field implementation blink.cmp.FuzzyImplementationType Controls which implementation to use for the fuzzy matcher. See the documentation for the available values for more information.
 --- @field max_typos number | fun(keyword: string): number Allows for a number of typos relative to the length of the query. Set this to 0 to match the behavior of fzf. Note, this does not apply when using the Lua implementation.
---- @field use_frecency boolean Tracks the most recently/frequently used items and boosts the score of the item. Note, this does not apply when using the Lua implementation.
+--- @field use_frecency boolean (deprecated) alias for frecency.enabled, will be removed in v2.0
+--- @field use_unsafe_no_lock boolean (deprecated) alias for frecency.unsafe_no_lock, will be removed in v2.0
 --- @field use_proximity boolean Boosts the score of items matching nearby words. Note, this does not apply when using the Lua implementation.
---- @field use_unsafe_no_lock boolean UNSAFE!! When enabled, disables the lock and fsync when writing to the frecency database. This should only be used on unsupported platforms (i.e. alpine termux). Note, this does not apply when using the Lua implementation.
 --- @field sorts blink.cmp.Sort[] Controls which sorts to use and in which order.
+--- @field frecency blink.cmp.FuzzyFrecencyConfig Tracks the most recently/frequently used items and boosts the score of the item. Note, this does not apply when using the Lua implementation.
 --- @field prebuilt_binaries blink.cmp.PrebuiltBinariesConfig
 
+--- @class (exact) blink.cmp.FuzzyFrecencyConfig
+--- @field enabled boolean Whether to enable the frecency feature
+--- @field path string Location of the frecency database
+--- @field unsafe_no_lock boolean UNSAFE!! When enabled, disables the lock and fsync when writing to the frecency database. This should only be used on unsupported platforms (i.e. alpine termux).
+
 --- @class (exact) blink.cmp.PrebuiltBinariesConfig
 --- @field download boolean Whenther 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`. Disabled by default when `fuzzy.implementation = 'lua'`
 --- @field ignore_version_mismatch boolean Ignores mismatched version between the built binary and the current git sha, when building locally
@@ -28,16 +34,21 @@
 --- @alias blink.cmp.SortFunction fun(a: blink.cmp.CompletionItem, b: blink.cmp.CompletionItem): boolean | nil
 --- @alias blink.cmp.Sort ("label" | "sort_text" | "kind" | "score" | "exact" | blink.cmp.SortFunction)
 
+local utils = require('blink.cmp.lib.utils')
 local validate = require('blink.cmp.config.utils').validate
+
 local fuzzy = {
   --- @type blink.cmp.FuzzyConfig
   default = {
     implementation = 'prefer_rust_with_warning',
     max_typos = function(keyword) return math.floor(#keyword / 4) end,
-    use_frecency = true,
     use_proximity = true,
-    use_unsafe_no_lock = false,
     sorts = { 'score', 'sort_text' },
+    frecency = {
+      enabled = true,
+      path = vim.fn.stdpath('state') .. '/blink/cmp/fuzzy.db',
+      unsafe_no_lock = false,
+    },
     prebuilt_binaries = {
       download = true,
       ignore_version_mismatch = false,
@@ -53,6 +64,45 @@ local fuzzy = {
 }
 
 function fuzzy.validate(config)
+  -- TODO: Deprecations to be removed in v2.0
+  if config.use_frecency ~= nil then
+    utils.notify({
+      { 'fuzzy.use_frecency', 'DiagnosticWarn' },
+      { ' is deprecated and has been replaced by ' },
+      { 'fuzzy.frecency.enabled', 'DiagnosticInfo' },
+      { '. Please update your config before version 2.0' },
+    })
+    config.frecency.enabled = config.use_frecency
+  end
+  if config.use_unsafe_no_lock ~= nil then
+    utils.notify({
+      { 'fuzzy.use_unsafe_no_lock', 'DiagnosticWarn' },
+      { ' is deprecated and has been replaced by ' },
+      { 'fuzzy.frecency.unsafe_no_lock', 'DiagnosticInfo' },
+      { '. Please update your config before version 2.0' },
+    })
+    config.frecency.unsafe_no_lock = config.use_unsafe_no_lock
+  end
+  -- Migrate the frecency database to its new location if needed
+  local deprecated_path = vim.fn.stdpath('data') .. '/blink/cmp/fuzzy.db'
+  if
+    config.frecency.enabled
+    and config.frecency.path ~= deprecated_path
+    and vim.fn.isdirectory(deprecated_path) == 1
+  then
+    local fromto_msg = ('from %s to %s'):format(deprecated_path, config.frecency.path)
+    local has_migrated = false
+    if vim.fn.mkdir(vim.fn.fnamemodify(config.frecency.path, ':h'), 'p') then
+      if vim.fn.rename(deprecated_path, config.frecency.path) == 0 then
+        has_migrated = true
+        utils.notify({ { 'Successfully migrated frecency database ' .. fromto_msg } })
+      end
+    end
+    if not has_migrated then
+      utils.notify({ { 'An error occured while migrating frecency database ' .. fromto_msg } })
+    end
+  end
+
   validate('fuzzy', {
     implementation = {
       config.implementation,
@@ -62,9 +112,7 @@ function fuzzy.validate(config)
       'one of: "prefer_rust", "prefer_rust_with_warning", "rust", "lua"',
     },
     max_typos = { config.max_typos, { 'number', 'function' } },
-    use_frecency = { config.use_frecency, 'boolean' },
     use_proximity = { config.use_proximity, 'boolean' },
-    use_unsafe_no_lock = { config.use_unsafe_no_lock, 'boolean' },
     sorts = {
       config.sorts,
       function(sorts)
@@ -80,9 +128,16 @@ function fuzzy.validate(config)
       end,
       'one of: "label", "sort_text", "kind", "score", "exact" or a function',
     },
+    frecency = { config.frecency, 'table' },
     prebuilt_binaries = { config.prebuilt_binaries, 'table' },
   }, config)
 
+  validate('fuzzy.frecency', {
+    enabled = { config.frecency.enabled, 'boolean' },
+    path = { config.frecency.path, 'string' },
+    unsafe_no_lock = { config.frecency.unsafe_no_lock, 'boolean' },
+  }, config.frecency)
+
   validate('fuzzy.prebuilt_binaries', {
     download = { config.prebuilt_binaries.download, 'boolean' },
     ignore_version_mismatch = { config.prebuilt_binaries.ignore_version_mismatch, 'boolean' },

lua/blink/cmp/fuzzy/init.lua

@@ -20,7 +20,7 @@ end
 function fuzzy.init_db()
   if fuzzy.has_init_db then return end
 
-  fuzzy.implementation.init_db(vim.fn.stdpath('data') .. '/blink/cmp/fuzzy.db', config.use_unsafe_no_lock)
+  fuzzy.implementation.init_db(config.fuzzy.frecency.path, config.fuzzy.frecency.unsafe_no_lock)
 
   vim.api.nvim_create_autocmd('VimLeavePre', {
     callback = fuzzy.implementation.destroy_db,
@@ -106,7 +106,7 @@ function fuzzy.fuzzy(line, cursor_col, haystacks_by_provider, range)
   local provider_ids = vim.tbl_keys(haystacks_by_provider)
   local provider_idxs, matched_indices, scores, exacts = fuzzy.implementation.fuzzy(line, cursor_col, provider_ids, {
     max_typos = max_typos,
-    use_frecency = config.fuzzy.use_frecency and keyword_length > 0,
+    use_frecency = config.fuzzy.frecency.enabled and keyword_length > 0,
     use_proximity = config.fuzzy.use_proximity and keyword_length > 0,
     nearby_words = nearby_words,
     match_suffix = range == 'full',