Inital commit.

lua/telescope/_extensions/frecency.lua

@@ -0,0 +1,84 @@
+local has_telescope, telescope = pcall(require, "telescope")
+
+-- TODO: make dependency errors occur in a better way
+if not has_telescope then
+  error("This plugin requires telescope.nvim (https://github.com/nvim-telescope/telescope.nvim)")
+end
+
+-- start the database client
+print("start")
+local db_client = require("telescope._extensions.frecency.db_client")
+vim.defer_fn(db_client.init, 100) -- TODO: this is a crappy attempt to lessen loadtime impact, use VimEnter?
+
+
+-- finder code
+
+-- local actions       = require "telescope.actions"
+local entry_display = require "telescope.pickers.entry_display"
+local finders       = require "telescope.finders"
+local pickers       = require "telescope.pickers"
+local previewers    = require "telescope.previewers"
+local sorters       = require "telescope.sorters"
+local conf          = require('telescope.config').values
+local path = require('telescope.path')
+local utils = require('telescope.utils')
+
+local frecency = function(opts)
+  opts = opts or {}
+
+  local cwd = vim.fn.expand(opts.cwd or vim.fn.getcwd())
+  local results = db_client.get_file_scores()
+  -- print(vim.inspect(results))
+
+  local displayer = entry_display.create {
+    separator = "",
+    hl_chars = { ["/"] = "TelescopePathSeparator"},
+    items = {
+      { width = 8 },
+      { remaining = true },
+    },
+  }
+
+  -- TODO: look into why this gets called so much
+  local make_display = function(entry)
+    local filename = entry.name
+
+    if opts.tail_path then
+      filename = utils.path_tail(filename)
+    elseif opts.shorten_path then
+      filename = utils.path_shorten(filename)
+    end
+
+    filename = path.make_relative(filename, cwd)
+
+    -- TODO: remove score from display; only there for debug
+    return displayer {
+      {entry.score, "Directory"}, filename
+    }
+  end
+
+  pickers.new(opts, {
+    prompt_title = "Frecency files",
+    finder = finders.new_table {
+      results = results,
+      entry_maker = function(entry)
+        return {
+          value   = entry.filename,
+          display = make_display,
+          ordinal = entry.filename,
+          name    = entry.filename,
+          score   = entry.score
+        }
+      end,
+    },
+    previewer = conf.file_previewer(opts),
+    sorter = sorters.get_generic_fuzzy_sorter(), -- TODO: do we have to have our own sorter? we only want filtering
+  }):find()
+end
+
+
+return telescope.register_extension {
+  exports = {
+    frecency = frecency,
+  },
+}

lua/telescope/_extensions/frecency/db_client.lua

@@ -0,0 +1,91 @@
+local sqlwrap   = require("telescope._extensions.frecency.sql_wrapper")
+
+local MAX_TIMESTAMPS = 10
+
+-- modifier used as a weight in the recency_score calculation:
+local recency_modifier = {
+  [1] = { age = 240   , value = 100 }, -- past 4 hours
+  [2] = { age = 1440  , value = 80  }, -- past day
+  [3] = { age = 4320  , value = 60  }, -- past 3 days
+  [4] = { age = 10080 , value = 40  }, -- past week
+  [5] = { age = 43200 , value = 20  }, -- past month
+  [6] = { age = 129600, value = 10  }  -- past 90 days
+}
+
+local sql_wrapper = nil
+
+local function init()
+  if sql_wrapper then return end
+
+  sql_wrapper = sqlwrap:new()
+  sql_wrapper:bootstrap()
+  print("setup")
+
+  -- setup autocommands
+  vim.api.nvim_command("augroup TelescopeFrecency")
+  vim.api.nvim_command("autocmd!")
+  vim.api.nvim_command("autocmd BufEnter * lua require'telescope._extensions.frecency.db_client'.autocmd_handler(vim.fn.expand('<amatch>'))")
+  vim.api.nvim_command("augroup END")
+end
+
+-- TODO: move these to util.lua
+local function string_isempty(s)
+  return s == nil or s == ''
+end
+
+local function calculate_file_score(frequency, timestamps)
+  local recency_score = 0
+  for _, ts in pairs(timestamps) do
+    for _, rank in ipairs(recency_modifier) do
+      if ts.age <= rank.age then
+        recency_score = recency_score + rank.value
+        goto continue
+      end
+    end
+    ::continue::
+  end
+
+  return frequency * recency_score / MAX_TIMESTAMPS
+end
+
+local function filter_timestamps(timestamps, file_id)
+  local res = {}
+  for _, entry in pairs(timestamps) do
+    if entry.file_id == file_id then
+      table.insert(res, entry)
+    end
+  end
+  return res
+end
+
+local function get_file_scores()
+  if not sql_wrapper then return end
+
+  local files           = sql_wrapper:do_transaction('get_all_filepaths')
+  local timestamp_ages  = sql_wrapper:do_transaction('get_all_timestamp_ages')
+
+  local scores = {}
+  for _, file_entry in ipairs(files) do
+    table.insert(scores, {
+      filename = file_entry.path,
+      score    = calculate_file_score(file_entry.count, filter_timestamps(timestamp_ages, file_entry.id))
+    })
+  end
+  return scores
+end
+
+local function autocmd_handler(filepath)
+  if not sql_wrapper or string_isempty(filepath) then return end
+
+  -- check if file is registered as loaded
+  if not vim.b.frecency_registered then
+    vim.b.frecency_registered = 1
+    sql_wrapper:update(filepath)
+  end
+end
+
+return {
+  init            = init,
+  get_file_scores = get_file_scores,
+  autocmd_handler = autocmd_handler,
+}

lua/telescope/_extensions/frecency/sql_wrapper.lua

@@ -0,0 +1,142 @@
+local vim = vim
+local uv  = vim.loop
+
+local has_sql, sql = pcall(require, "sql")
+if not has_sql then
+  error("This plugin requires sql.nvim (https://github.com/tami5/sql.nvim)")
+end
+
+-- TODO: pass in max_timestamps from db.lua
+local MAX_TIMESTAMPS = 10
+
+-- TODO: prioritize files in project root!
+
+local schemas = {[[
+  CREATE TABLE IF NOT EXISTS files (
+    id                    INTEGER PRIMARY KEY,
+    count                 INTEGER,
+    path                  TEXT
+  );
+]],
+[[
+  CREATE TABLE IF NOT EXISTS timestamps (
+    id                    INTEGER PRIMARY KEY,
+    file_id               INTEGER,
+    timestamp             REAL,
+    FOREIGN KEY(file_id)  REFERENCES files(id)
+  );
+]]}
+
+local queries = {
+  ["file_add_entry"]              = "INSERT INTO files (path, count) values(:path, 1);",
+  ["file_update_counter"]         = "UPDATE files SET count = count + 1 WHERE path = :path;",
+  ["timestamp_add_entry"]         = "INSERT INTO timestamps (file_id, timestamp) values(:file_id, julianday('now'));",
+  ["timestamp_delete_before_id"]  = "DELETE FROM timestamps WHERE id < :id and file_id == :file_id;",
+  ["get_all_filepaths"]           = "SELECT * FROM files;",
+  ["get_all_timestamp_ages"]      = "SELECT id, file_id, CAST((julianday('now') - julianday(timestamp)) * 24 * 60 AS INTEGER) AS age FROM timestamps;",
+  ["get_row"]                     = "SELECT * FROM files WHERE path == :path;",
+  ["get_timestamp_ids_for_file"]  = "SELECT id FROM timestamps WHERE file_id == :file_id;",
+}
+
+-- local ignore_patterns = {
+-- }
+
+--
+local function fs_stat(path)  -- TODO: move this to new file with M
+  local stat = uv.fs_stat(path)
+  local res  = {}
+  res.exists      = stat and true or false -- TODO: this is silly
+  res.isdirectory = (stat and stat.type == "directory") and true or false
+
+  return res
+end
+
+local M = {}
+M.queries = queries
+
+function M:new()
+  local o = {}
+  setmetatable(o, self)
+  self.__index = self
+  self.db = nil
+
+  return o
+end
+
+function M:bootstrap(opts)
+  opts = opts or {}
+
+  if self.db then
+    print("sql wrapper already initialised")
+    return
+  end
+
+  self.max_entries = opts.max_entries or 2000
+
+  -- create the db if it doesn't exist
+  local db_root = opts.docs_root or "$XDG_DATA_HOME/nvim"
+  local db_filename = db_root .. "/file_frecency.sqlite3"
+  self.db = sql.open(db_filename)
+  if not self.db then
+    print("error")
+    return
+  end
+
+  -- create tables if they don't exist
+  for _, s in pairs(schemas) do
+    self.db:eval(s)
+  end
+  self.db:close()
+
+end
+
+function M:do_transaction(query, params)
+  if not queries[query] then
+    print("invalid query_preset: " .. query )
+    return
+  end
+
+  local res
+  self.db:with_open(function(db) res = db:eval(queries[query], params) end)
+  return res
+end
+
+function M:get_row_id(filepath)
+  local result = self:do_transaction('get_row', { path = filepath })
+
+  return type(result) == "table" and result[1].id or nil
+end
+
+function M:update(filepath)
+  local filestat = fs_stat(filepath)
+  if (vim.tbl_isempty(filestat) or
+      filestat.exists       == false or
+      filestat.isdirectory  == true) then
+      return end
+
+  -- create entry if it doesn't exist
+  local file_id
+  file_id = self:get_row_id(filepath)
+  if not file_id then
+    self:do_transaction('file_add_entry', { path = filepath })
+    file_id = self:get_row_id(filepath)
+  else
+  -- ..or update existing entry
+    self:do_transaction('file_update_counter', { path = filepath })
+  end
+
+  -- register timestamp for this update
+  self:do_transaction('timestamp_add_entry', { file_id = file_id })
+
+  -- trim timestamps to MAX_TIMESTAMPS per file (there should be up to MAX_TS + 1 at this point)
+  local timestamps = self:do_transaction('get_timestamp_ids_for_file', { file_id = file_id })
+  local trim_at = timestamps[(#timestamps - MAX_TIMESTAMPS) + 1]
+  if trim_at then
+    self:do_transaction('timestamp_delete_before_id', { id = trim_at.id, file_id = file_id })
+  end
+end
+
+function M:validate()
+end
+
+return M