refactor(git): split URI read from conditional refresh

lua/git/object.lua

@@ -71,6 +71,20 @@ local function is_zero(sha)
     return sha == nil or sha:match("^0+$") ~= nil
 end
 
+---@param rev ow.Git.Revision
+---@return boolean
+local function is_immutable_rev(rev)
+    if rev.stage ~= nil then
+        return false
+    end
+    local base = rev.base
+    if not base then
+        return false
+    end
+    local stripped = base:gsub("%^%b{}", ""):gsub("[%^~]%d*", "")
+    return stripped:match("^%x+$") ~= nil and #stripped >= 7
+end
+
 ---@param buf integer
 ---@param r ow.Git.Repo
 ---@param path string
@@ -141,23 +155,16 @@ end
 
 ---@param r ow.Git.Repo
 ---@param rev ow.Git.Revision
----@param content string?
 ---@return integer
-function M.buf_for(r, rev, content)
+function M.buf_for(r, rev)
     local buf = vim.fn.bufadd(M.format_uri(rev))
     repo.bind(buf, r)
-    if content and not vim.api.nvim_buf_is_loaded(buf) then
-        local state = r:state(buf) --[[@as -nil]]
-        state.pending_content = content
-    end
     vim.fn.bufload(buf)
     return buf
 end
 
 ---@param buf integer
----@param opts { force?: boolean }?
-function M.read_uri(buf, opts)
-    opts = opts or {}
+function M.read_uri(buf)
     local name = vim.api.nvim_buf_get_name(buf)
     local rev = M.parse_uri(name)
     if not rev then
@@ -176,27 +183,20 @@ function M.read_uri(buf, opts)
     vim.bo[buf].swapfile = false
     vim.bo[buf].bufhidden = "hide"
 
-    ---@type string?
-    local stdout = state.pending_content
-    state.pending_content = nil
-    if stdout == nil then
-        local rev_sha = r:rev_parse(rev_str, true)
-        if not rev_sha then
-            return
-        end
-        if
-            not opts.force
-            and (rev_sha == state.sha or vim.bo[buf].modified)
-        then
-            return
-        end
-        stdout = util.exec(
-            { "git", "cat-file", "-p", rev_str },
-            { cwd = r.worktree }
-        )
+    local rev_sha = r:rev_parse(rev_str, true)
+    if not rev_sha then
+        return
     end
 
-    if stdout and rev.path == nil then
+    local stdout = util.exec(
+        { "git", "cat-file", "-p", rev_str },
+        { cwd = r.worktree }
+    )
+    if not stdout then
+        return
+    end
+
+    if rev.path == nil then
         local commit_sha = r:rev_parse(rev_str .. "^{commit}", true)
         if commit_sha then
             local patch = util.exec({
@@ -216,12 +216,11 @@ function M.read_uri(buf, opts)
         end
     end
 
-    if stdout then
-        vim.bo[buf].modifiable = true
-        vim.api.nvim_buf_set_lines(buf, 0, -1, false, util.split_lines(stdout))
-    end
+    vim.bo[buf].modifiable = true
+    vim.api.nvim_buf_set_lines(buf, 0, -1, false, util.split_lines(stdout))
 
-    state.sha = r:rev_parse(rev_str, true)
+    state.sha = rev_sha
+    state.immutable = is_immutable_rev(rev)
 
     if rev.stage == 0 and rev.path then
         vim.bo[buf].buftype = "acwrite"
@@ -249,6 +248,24 @@ function M.read_uri(buf, opts)
     vim.api.nvim_exec_autocmds("BufReadPost", { buffer = buf })
 end
 
+---@param buf integer
+---@param r ow.Git.Repo
+local function refresh(buf, r)
+    local state = r:state(buf)
+    if not state or state.immutable or vim.bo[buf].modified then
+        return
+    end
+    local rev = M.parse_uri(vim.api.nvim_buf_get_name(buf))
+    if not rev then
+        return
+    end
+    local rev_sha = r:rev_parse(rev:format(), true)
+    if not rev_sha or rev_sha == state.sha then
+        return
+    end
+    M.read_uri(buf)
+end
+
 ---@param r ow.Git.Repo
 ---@param blob string?
 ---@param path string
@@ -314,15 +331,11 @@ function M.open(r, rev, opts)
             parsed.base = sha
         end
     end
-    local content = util.exec(
-        { "git", "cat-file", "-p", parsed:format() },
-        { cwd = r.worktree, silent = true }
-    )
-    if not content then
+    if not r:rev_parse(parsed:format(), true) then
         util.error("not a git object: %s", rev)
         return
     end
-    local buf = M.buf_for(r, parsed, content)
+    local buf = M.buf_for(r, parsed)
     util.place_buf(buf, opts and opts.split)
 end
 
@@ -384,6 +397,6 @@ function M.open_under_cursor()
     return false
 end
 
-repo.on_uri_refresh(M.URI_PREFIX, M.read_uri)
+repo.on_uri_refresh(M.URI_PREFIX, refresh)
 
 return M