[tool,man,db] add --max-fonts option to restrict db size

3 files changed, 27 insertions, 9 deletions

diff --git a/luaotfload-database.lua b/luaotfload-database.lua
index a12cdd1..4ee07f4 100644
--- a/luaotfload-database.lua
+++ b/luaotfload-database.lua
@@ -533,6 +533,7 @@ local set_font_filter
 
 --- state of the database
 local fonts_reloaded = false
+local fonts_read     = 0
 
 --- limit output when approximate font matching (luaotfload-tool -F)
 local fuzzy_limit = 1 --- display closest only
@@ -2112,15 +2113,20 @@ local scan_dir = function (dirname, currentnames, targetnames,
         local fullname = found[j]
         fullname = path_normalize(fullname)
         local new
-        if dry_run == true then
-            report_status ("both", "db",
-                           "Would have been loading %q", fullname)
-        else
-            report_status ("both", "db", "Loading font %q", fullname)
-            local new = read_font_names (fullname, currentnames,
-                                         targetnames, texmf)
-            if new == true then
-                n_new = n_new + 1
+        if not luaotfloadconfig.max_fonts
+            or luaotfloadconfig.max_fonts and fonts_read < luaotfloadconfig.max_fonts
+        then
+            if dry_run == true then
+                report_status ("both", "db",
+                            "Would have been loading %q", fullname)
+            else
+                report_status ("both", "db", "Loading font %q", fullname)
+                local new = read_font_names (fullname, currentnames,
+                                            targetnames, texmf)
+                if new == true then
+                    fonts_read = fonts_read + 1
+                    n_new = n_new + 1
+                end
             end
         end
     end
diff --git a/luaotfload-tool.lua b/luaotfload-tool.lua
index f1e4808..41ac4d7 100755
--- a/luaotfload-tool.lua
+++ b/luaotfload-tool.lua
@@ -225,6 +225,7 @@ This tool is part of the luaotfload package. Valid options are:
   -D --dry-run                 skip loading of fonts, just scan
   --formats=[+|-]EXTENSIONS    set, add, or subtract formats to index
   -p --prefer-texmf            prefer fonts in the TEXMF over system fonts
+  --max-fonts=N                process at most N font files
 
   --find="font name"           query the database for a font name
   -F --fuzzy                   look for approximate matches if --find fails
@@ -1114,6 +1115,7 @@ local process_cmdline = function ( ) -- unit -> jobspec
         limit              = 1,
         list               = 1,
         log                = 1,
+        ["max-fonts"]      = 1,
         ["no-reload"]      = "n",
         ["no-strip"]       = 0,
         ["skip-read"]      = "R",
@@ -1219,6 +1221,14 @@ local process_cmdline = function ( ) -- unit -> jobspec
             luaotfloadconfig.compress = false
         elseif v == "no-strip" then
             luaotfloadconfig.strip = false
+        elseif v == "max-fonts" then
+            local n = optarg[n]
+            if n then
+                n = tonumber(lvl)
+                if n and n > 0 then
+                    luaotfloadconfig.max_fonts = n
+                end
+            end
         end
     end
 
diff --git a/luaotfload-tool.rst b/luaotfload-tool.rst
index abe5ed7..957ec85 100644
--- a/luaotfload-tool.rst
+++ b/luaotfload-tool.rst
@@ -74,6 +74,8 @@ update mode
 --prefer-texmf, -p      Organize the file name database in a way so
                         that it prefer fonts in the *TEXMF* tree over
                         system fonts if they are installed in both.
+--max-fonts=N           Process at most *N* font files, including fonts
+                        already indexed in the count.
 --formats=EXTENSIONS    Extensions of the font files to index.
                         Where *EXTENSIONS* is a comma-separated list of
                         supported file extensions (otf, ttf, ttc,