Prepare web server with embedded files

extra_pre.py

@@ -0,0 +1,164 @@
+print("running extra script...")
+
+import os
+import sys
+import inspect
+import gzip
+import shutil
+
+Import("env")
+
+GEN_DIR = 'lib/generated'
+OWN_FILE = "extra_script.py"
+
+INDEXJS = "index.js"
+INDEXCSS = "index.css"
+
+# embedded files definition is generated inside here
+EMBEDDED_INCLUDE="embeddedfiles.h"
+
+def basePath():
+    #see: https://stackoverflow.com/questions/16771894/python-nameerror-global-name-file-is-not-defined
+    return os.path.dirname(inspect.getfile(lambda: None))
+
+def is_current(infile, outfile):
+    if os.path.exists(outfile):
+        otime = os.path.getmtime(outfile)
+        itime = os.path.getmtime(infile)
+        if (otime >= itime):
+            own = os.path.join(basePath(), OWN_FILE)
+            if os.path.exists(own):
+                owntime = os.path.getmtime(own)
+                if owntime > otime:
+                    return False
+            print(f"{outfile} is newer than {infile}, no need to recreate")
+            return True
+    return False
+
+def compress_file(infile, outfile):
+    if is_current(infile, outfile):
+        return
+    print(f"compressing {infile}")
+    with open(infile, 'rb') as f_in:
+        with gzip.open(outfile, 'wb') as f_out:
+            shutil.copyfileobj(f_in, f_out)
+
+def write_file_if_changed(filename, data):
+    """
+    Create or update file if it not contains data as content
+    """
+    if os.path.exists(filename):
+        changetype = 'updating'
+        with open(filename, 'r') as fh:
+            if fh.read() == data:
+                print(f"{filename} is up to date")
+                return False
+    else:
+        changetype = 'generating'
+    print(f"#{changetype} {filename}")
+    with open(filename, 'w') as fh:
+        fh.write(data)
+    return True
+
+def get_embedded_files(env):
+    filelist = []
+    efiles = env.GetProjectOption("board_build.embed_files")
+    for f in efiles.split("\n"):
+        if f == '':
+            continue
+        filelist.append(f)
+    return filelist  
+
+def get_content_type(fn):
+    if (fn.endswith('.gz')):
+        fn = fn[0:-3]
+    if (fn.endswith('html')):
+        return "text/html"
+    if (fn.endswith('json')):
+        return "application/json"
+    if (fn.endswith('js')):
+        return "text/javascript"
+    if (fn.endswith('css')):
+        return "text/css"
+    if (fn.endswith('png')):
+        return "image/png"
+    if (fn.endswith('jpg') or fn.endswith('jpeg')):
+        return "image/jpeg"
+    return "application/octet-stream"
+
+def join_files(target, filename, dirlist):
+    """
+    Join files named filename within different directories
+    into one single gzip archive (located in generated dir)
+    """
+    print("joinfiles: {} into {} from dirs [{}]".format(filename, target, ','.join(dirlist)))
+    flist = []
+    for dir in dirlist:
+        fn = os.path.join(dir, filename)
+        if os.path.exists(fn):
+            flist.append(fn)
+    current = False
+    if os.path.exists(target):
+        current = True
+        for f in flist:
+            if not is_current(f, target):
+                current = False
+                break
+    if current:
+        print(f"{target} is up to date")
+        return
+    print(f"creating {target}")
+
+    # add multiple files
+    with gzip.open(target, "wb") as oh:
+        for fn in flist:
+            print("adding {} to {}".format(fn, target))
+            with open(fn, "rb") as rh:
+                shutil.copyfileobj(rh, oh)
+
+def prebuild(env):
+    print("#prebuild running")
+
+    # directory for dynamically generated files
+    gendir = os.path.join(basePath(), GEN_DIR)
+    if not os.path.exists(gendir):
+        os.makedirs(gendir)
+    if not os.path.isdir(gendir):
+        print("unable to create directory {}".format(gendir))
+        sys.exit(1)
+
+    # join static web server files
+
+    # only useful for different task dirs with custom configs
+    # join_files(os.path.join(gendir, INDEXJS+".gz"), INDEXJS, ["web"])
+    # join_files(os.path.join(gendir, INDEXCSS+".gz"), INDEXCSS, ["web"])
+
+    # platformio defined embedded files as list
+    pio_embedded = get_embedded_files(env)
+
+    filedefs = []
+    for ef in pio_embedded:
+        print(f"#checking embedded file {ef}")
+        # files are defined with relative path to platformio.ini
+        # the name can be with extension gz or without
+        (dn, fn) = os.path.split(ef)
+        pureName = fn
+        if pureName.endswith('.gz'):
+            pureName = pureName[0:-3]
+        usname = ef.replace('/','_').replace('.','_') # sanitize filenames
+        filedefs.append((pureName, usname, get_content_type(pureName)))
+        infile = os.path.join(basePath(), "web", pureName)
+        if os.path.exists(infile):
+            compress_file(infile, ef)
+        else:
+            print("#WARNING: infile {infile} for {ef} not found")
+
+    # generate c-header file for embedding zip files
+    content = ""
+    for entry in filedefs:
+        content += 'EMBED_GZ_FILE("{}", {}, "{}");\n'.format(*entry)
+    write_file_if_changed(os.path.join(gendir, EMBEDDED_INCLUDE), content)  
+
+print("#prescript...")
+prebuild(env)
+