add async managers (#536)

1 files changed, 167 insertions, 0 deletions

diff --git a/lua/nvim-lsp-installer/core/context.lua b/lua/nvim-lsp-installer/core/context.lua
new file mode 100644
index 00000000..128ad417
--- /dev/null
+++ b/lua/nvim-lsp-installer/core/context.lua
@@ -0,0 +1,167 @@
+local spawn = require "nvim-lsp-installer.core.spawn"
+local log = require "nvim-lsp-installer.log"
+local Optional = require "nvim-lsp-installer.core.optional"
+local fs = require "nvim-lsp-installer.core.fs"
+local settings = require "nvim-lsp-installer.settings"
+local Result = require "nvim-lsp-installer.core.result"
+local path = require "nvim-lsp-installer.path"
+local platform = require "nvim-lsp-installer.platform"
+
+---@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
+local CwdManager = {}
+CwdManager.__index = CwdManager
+function CwdManager.new(cwd)
+    return setmetatable({ cwd = cwd }, CwdManager)
+end
+function CwdManager:get()
+    return self.cwd
+end
+function CwdManager:set(new_cwd)
+    self.cwd = new_cwd
+end
+
+---@class InstallContext
+---@field public receipt InstallReceiptBuilder
+---@field public requested_version Optional
+---@field public fs ContextualFs
+---@field public spawn JobSpawn
+---@field private cwd_manager CwdManager
+---@field private destination_dir string
+local InstallContext = {}
+InstallContext.__index = InstallContext
+
+function InstallContext.new(opts)
+    local cwd_manager = CwdManager.new(opts.cwd)
+    return setmetatable({
+        cwd_manager = cwd_manager,
+        spawn = ContextualSpawn.new(cwd_manager, opts.stdio_sink),
+        fs = ContextualFs.new(cwd_manager),
+        receipt = opts.receipt,
+        requested_version = opts.requested_version,
+        destination_dir = opts.destination_dir,
+    }, InstallContext)
+end
+
+---@deprecated
+---@param ctx ServerInstallContext
+---@param destination_dir string
+function InstallContext.from_server_context(ctx, destination_dir)
+    return InstallContext.new {
+        cwd = ctx.install_dir,
+        receipt = ctx.receipt,
+        stdio_sink = ctx.stdio_sink,
+        requested_version = Optional.of_nilable(ctx.requested_server_version),
+        destination_dir = destination_dir,
+    }
+end
+
+function InstallContext:cwd()
+    return self.cwd_manager:get()
+end
+
+---@param new_cwd string @The new cwd (absolute path).
+function InstallContext:set_cwd(new_cwd)
+    self
+        :ensure_path_ownership(new_cwd)
+        :map(function(p)
+            self.cwd_manager:set(p)
+            return p
+        end)
+        :get_or_throw()
+end
+
+---@param abs_path string
+function InstallContext:ensure_path_ownership(abs_path)
+    if path.is_subdirectory(self:cwd_manager(), abs_path) or self.destination_dir == abs_path then
+        return Result.success(abs_path)
+    else
+        return Result.failure(
+            ("Path %q is outside of current path ownership (%q)."):format(abs_path, settings.current.install_root_dir)
+        )
+    end
+end
+
+---@async
+function InstallContext:promote_cwd()
+    local cwd = self:cwd()
+    if self.destination_dir == cwd then
+        log.fmt_debug("cwd %s is already promoted (at %s)", cwd, self.destination_dir)
+        return Result.success "Current working dir is already in destination."
+    end
+    log.fmt_debug("Promoting cwd %s to %s", cwd, self.destination_dir)
+    return Result.run_catching(function()
+        -- 1. Remove destination dir, if it exists
+        if fs.dir_exists(self.destination_dir) then
+            fs.rmrf(self.destination_dir)
+        end
+        return self.destination_dir
+    end)
+        :map_catching(function(destination_dir)
+            -- 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(destination_dir)
+            end
+            return destination_dir
+        end)
+        :map_catching(function(destination_dir)
+            -- 3. Move the cwd to the final installation directory
+            fs.rename(cwd, destination_dir)
+            return destination_dir
+        end)
+        :map_catching(function(destination_dir)
+            -- 4. Update cwd
+            self:set_cwd(destination_dir)
+        end)
+end
+
+return InstallContext