switch majority of installers to async implementation (#574)

1 files changed, 134 insertions, 0 deletions

diff --git a/lua/nvim-lsp-installer/core/installer/context.lua b/lua/nvim-lsp-installer/core/installer/context.lua
new file mode 100644
index 00000000..ad956178
--- /dev/null
+++ b/lua/nvim-lsp-installer/core/installer/context.lua
@@ -0,0 +1,134 @@
+local spawn = require "nvim-lsp-installer.core.spawn"
+local log = require "nvim-lsp-installer.log"
+local fs = require "nvim-lsp-installer.core.fs"
+local path = require "nvim-lsp-installer.path"
+local platform = require "nvim-lsp-installer.platform"
+local receipt = require "nvim-lsp-installer.core.receipt"
+
+---@class ContextualSpawn
+---@field cwd CwdManager
+---@field stdio_sink StdioSink
+local ContextualSpawn = {}
+
+---@param cwd CwdManager
+---@param stdio_sink StdioSink
+function ContextualSpawn.new(cwd, stdio_sink)
+    return setmetatable({ cwd = cwd, stdio_sink = stdio_sink }, ContextualSpawn)
+end
+function ContextualSpawn.__index(self, cmd)
+    return function(args)
+        args.cwd = args.cwd or self.cwd:get()
+        args.stdio_sink = args.stdio_sink or self.stdio_sink
+        -- We get_or_throw() here for convenience reasons.
+        -- Almost every time spawn is called via context we want the command to succeed.
+        return spawn[cmd](args):get_or_throw()
+    end
+end
+
+---@class ContextualFs
+---@field private cwd CwdManager
+local ContextualFs = {}
+ContextualFs.__index = ContextualFs
+
+---@param cwd CwdManager
+function ContextualFs.new(cwd)
+    return setmetatable({ cwd = cwd }, ContextualFs)
+end
+
+---@async
+---@param rel_path string @The relative path from the current working directory to the file to append.
+---@param contents string
+function ContextualFs:append_file(rel_path, contents)
+    return fs.append_file(path.concat { self.cwd:get(), rel_path }, contents)
+end
+
+---@async
+---@param rel_path string @The relative path from the current working directory.
+function ContextualFs:file_exists(rel_path)
+    return fs.file_exists(path.concat { self.cwd:get(), rel_path })
+end
+
+---@async
+---@param rel_path string @The relative path from the current working directory.
+function ContextualFs:dir_exists(rel_path)
+    return fs.dir_exists(path.concat { self.cwd:get(), rel_path })
+end
+
+---@class CwdManager
+---@field private boundary_path string @Defines the upper boundary for which paths are allowed as cwd.
+---@field private cwd string
+local CwdManager = {}
+CwdManager.__index = CwdManager
+
+function CwdManager.new(boundary_path, cwd)
+    assert(type(boundary_path) == "string")
+    return setmetatable({
+        boundary_path = boundary_path,
+        cwd = cwd,
+    }, CwdManager)
+end
+
+function CwdManager:get()
+    return assert(self.cwd, "Tried to access cwd before it was set.")
+end
+
+---@param new_cwd string
+function CwdManager:set(new_cwd)
+    assert(type(new_cwd) == "string")
+    assert(
+        path.is_subdirectory(self.boundary_path, new_cwd),
+        ("%q is not a subdirectory of %q"):format(new_cwd, self.boundary_path)
+    )
+    self.cwd = new_cwd
+end
+
+---@class InstallContext
+---@field public name string
+---@field public receipt InstallReceiptBuilder
+---@field public requested_version Optional
+---@field public fs ContextualFs
+---@field public spawn JobSpawn
+---@field public cwd CwdManager
+---@field public destination_dir string
+---@field public stdio_sink StdioSink
+local InstallContext = {}
+InstallContext.__index = InstallContext
+
+function InstallContext.new(opts)
+    local cwd_manager = CwdManager.new(opts.boundary_path)
+    return setmetatable({
+        name = opts.name,
+        cwd = cwd_manager,
+        spawn = ContextualSpawn.new(cwd_manager, opts.stdio_sink),
+        fs = ContextualFs.new(cwd_manager),
+        receipt = receipt.InstallReceiptBuilder.new(),
+        destination_dir = opts.destination_dir,
+        requested_version = opts.requested_version,
+        stdio_sink = opts.stdio_sink,
+    }, InstallContext)
+end
+
+---@async
+function InstallContext:promote_cwd()
+    local cwd = self.cwd:get()
+    if self.destination_dir == cwd then
+        log.fmt_debug("cwd %s is already promoted (at %s)", cwd, self.destination_dir)
+        return
+    end
+    log.fmt_debug("Promoting cwd %s to %s", cwd, self.destination_dir)
+    -- 1. Remove destination dir, if it exists
+    if fs.dir_exists(self.destination_dir) then
+        fs.rmrf(self.destination_dir)
+    end
+    -- 2. Prepare for renaming cwd to destination
+    if platform.is_unix then
+        -- Some Unix systems will raise an error when renaming a directory to a destination that does not already exist.
+        fs.mkdir(self.destination_dir)
+    end
+    -- 3. Move the cwd to the final installation directory
+    fs.rename(cwd, self.destination_dir)
+    -- 4. Update cwd
+    self.cwd:set(self.destination_dir)
+end
+
+return InstallContext