local dvireader = require "make4ht-dvireader"
local mkutils = require "mkutils"
local filter = require "make4ht-filter"
local log = logging.new "dvisvgm_hashes"
local dvisvgm_par = {}
local M = {}
-- mapping between tex4ht image names and hashed image names
local output_map = {}
local dvisvgm_options = "-n --exact -c ${scale},${scale}"
local parallel_size = 64
local make_command = "make -j ${process_count} -f ${make_file}"
local test_make_command = "make -v"
-- local parallel_size = 3
local function make_hashed_name(base, hash)
return base .. "-" ..hash..".svg"
end
-- detect the number of available processors
local cpu_cnt = 3 -- set a reasonable default for non-Linux systems
if os.name == 'linux' then
cpu_cnt = 0
local cpuinfo=assert(io.open('/proc/cpuinfo', 'r'))
for line in cpuinfo:lines() do
if line:match('^processor') then
cpu_cnt = cpu_cnt + 1
end
end
-- set default number of threds if no CPU core have been found
if cpu_cnt == 0 then cpu_cnt = 1 end
cpuinfo:close()
elseif os.name == 'cygwin' or os.type == 'windows' then
-- windows has NUMBER_OF_PROCESSORS environmental value
local nop = os.getenv('NUMBER_OF_PROCESSORS')
if tonumber(nop) then
cpu_cnt = nop
end
end
-- process output of dvisvgm and find output page numbers and corresponding files
local function get_generated_pages(output, pages)
local pages = pages or {}
local pos = 1
local pos, finish, page = string.find(output, "processing page (%d+)", pos)
while(pos) do
pos, finish, file = string.find(output, "output written to ([^\n^\r]+)", finish)
pages[tonumber(page)] = file
if not finish then break end
pos, finish, page = string.find(output, "processing page (%d+)", finish)
end
return pages
end
local function make_ranges(pages)
local newpages = {}
local start, stop
for i=1,#pages do
local current = pages[i]
local next_el = pages[i+1] or current + 100 -- just select a big number
local diff = next_el - current
if diff == 1 then
if not start then start = current end
else
local element
if start then
element = start .. "-" .. current
else
element = current
end
newpages[#newpages+1] = element
start = nil
end
end
return newpages
end
local function read_log(dvisvgmlog)
local f = io.open(dvisvgmlog, "rb")
if not f then return nil, "Cannot read dvisvgm log" end
local output = f:read("*all")
f:close()
return output
end
-- test the existence of GNU Make, which can execute tasks in parallel
local function test_make()
local make = io.popen(test_make_command, "r")
local content = make:read("*all")
make:close()
-- io.popen always returns valid handle, so we can find that the command doesn't exists only by checking that the
-- content is empty
return content~=nil and content ~= ""
end
local function save_file(filename, text)
local f = io.open(filename, "w")
f:write(text)
f:close()
end
local function make_makefile_command(idvfile, page_sequences)
local logs = {}
local all = {} -- list of targets in the "all:" makefile target
local targets = {}
local basename = idvfile:gsub(".idv$", "")
local makefilename = basename .. "-images" .. ".mk"
-- build make targets
for i, ranges in ipairs(page_sequences) do
local target = basename .. "-" .. i
local logfile = target .. ".dlog"
logs[#logs + 1] = logfile
all[#all+1] = target
local chunk = target .. ":\n\tdvisvgm -v4 " .. dvisvgm_options .. " -p " .. ranges .. " " .. idvfile .. " 2> " .. logfile .. "\n"
targets[#targets + 1] = chunk
end
-- construct makefile and save it
local makefile = "all: " .. table.concat(all, " ") .. "\n\n" .. table.concat(targets, "\n")
save_file(makefilename, makefile)
local command = make_command % {process_count = cpu_cnt, make_file = makefilename}
log:debug("Makefile command: " .. command)
return command, logs
end
local function prepare_command(idvfile, pages)
local logs = {}
if #pages > parallel_size and test_make() then
local page_sequences = {}
for i=1, #pages, parallel_size do
local current_pages = {}
for x = i, i+parallel_size -1 do
current_pages[#current_pages + 1] = pages[x]
end
table.insert(page_sequences,table.concat(make_ranges(current_pages), ","))
end
return make_makefile_command(idvfile, page_sequences)
end
-- else
local pagesequence = table.concat(make_ranges(pages), ",")
-- the stderr from dvisvgm must be redirected and postprocessed
local dvisvgmlog = idvfile:gsub("idv$", "dlog")
-- local dvisvgm = io.popen("dvisvgm -v4 -n --exact -c 1.15,1.15 -p " .. pagesequence .. " " .. idvfile, "r")
local command = "dvisvgm -v4 " .. dvisvgm_options .. " -p " .. pagesequence .. " " .. idvfile .. " 2> " .. dvisvgmlog
return command, {dvisvgmlog}
-- end
end
local function execute_dvisvgm(idvfile, pages)
if #pages < 1 then return nil, "No pages to convert" end
local command, logs = prepare_command(idvfile, pages)
log:info(command)
os.execute(command)
local generated_pages = {}
for _, dvisvgmlog in ipairs(logs) do
local output = read_log(dvisvgmlog)
generated_pages = get_generated_pages(output, generated_pages)
end
return generated_pages
end
local function get_dvi_pages(arg)
-- list of pages to convert in this run
local to_convert = {}
local idv_file = arg.input .. ".idv"
-- set extension options
local extoptions = mkutils.get_filter_settings "dvisvgm_hashes" or {}
dvisvgm_options = arg.options or extoptions.options or dvisvgm_options
parallel_size = arg.parallel_size or extoptions.parallel_size or parallel_size
cpu_cnt = arg.cpu_cnt or extoptions.cpu_cnt or cpu_cnt
dvisvgm_par.scale = arg.scale or extoptions.scale or 1.4
dvisvgm_options = dvisvgm_options % dvisvgm_par
make_command = arg.make_command or extoptions.make_command or make_command
test_make_command = arg.test_make_command or extoptions.test_make_command or test_make_command
local f = io.open(idv_file, "rb")
if not f then return nil, "Cannot open idv file: " .. idv_file end
local content = f:read("*all")
f:close()
local dvi_pages = dvireader.get_pages(content)
-- we must find page numbers and output name sfor the generated images
local lg = mkutils.parse_lg(arg.input ..".lg", arg.builddir)
for _, name in ipairs(lg.images) do
local page = tonumber(name.page)
local hash = dvi_pages[page]
local tex4ht_name = name.output
local output_name = make_hashed_name(arg.input, hash)
output_map[tex4ht_name] = output_name
if not mkutils.file_exists(output_name) then
log:debug("output file: ".. output_name)
to_convert[#to_convert+1] = page
end
end
local generated_files, msg = execute_dvisvgm(idv_file, to_convert)
if not generated_files then
return nil, msg
end
-- rename the generated files to the hashed filenames
for page, file in pairs(generated_files) do
os.rename(file, make_hashed_name(arg.input, dvi_pages[page]))
end
end
function M.test(format)
-- ODT format doesn't support SVG
if format == "odt" then return false end
return true
end
function M.modify_build(make)
-- this must be used in the .mk4 file as
-- Make:dvisvgm_hashes {}
make:add("dvisvgm_hashes", function(arg)
get_dvi_pages(arg)
end,
{
})
-- insert dvisvgm_hashes command at the end of the build sequence -- it needs to be called after t4ht
make:dvisvgm_hashes {}
-- replace original image names with hashed names
local executed = false
make:match(".*", function(arg)
if not executed then
executed = true
local lgfiles = make.lgfile.files
for i, filename in ipairs(lgfiles) do
local replace = output_map[filename]
if replace then
lgfiles[i] = replace
end
end
-- tex4ebook process also the images table, so we need to replace generated filenames here as well
local lgimages = make.lgfile.images
for _, image in ipairs(lgimages) do
local replace = output_map[image.output]
if replace then
image.output = replace
end
end
end
end)
-- fix src attributes
local process = filter({
function(str, filename)
return str:gsub('src=["\'](.-)(["\'])', function(filename, endquote)
local newname = output_map[filename] or filename
log:debug("newname", newname)
return 'src=' .. endquote .. newname .. endquote
end)
end
}, "dvisvgmhashes")
make:match("htm.?$", process)
-- disable the image processing
for _,v in ipairs(make.build_seq) do
if v.name == "t4ht" then
local t4ht_par = v.params.t4ht_par or make.params.t4ht_par or ""
v.params.t4ht_par = t4ht_par .. " -p"
end
end
make:image(".", function() return "" end)
return make
end
