[libvirt] [PATCH] Generate status of the backend implementation in storage.html

[Cedric Bosdonnat]

Since it helps a user to know which of the storage backends support what
operation, include an autogenerated matrix showing it in the docs.
---
 .gitignore                   |  1 +
 docs/Makefile.am             |  9 +++--
 docs/apibuild.py             |  2 ++
 docs/storage.html.in         | 14 ++++++++
 docs/storagebackendstatus.py | 64 ++++++++++++++++++++++++++++++++++++
 5 files changed, 88 insertions(+), 2 deletions(-)
 create mode 100644 docs/storagebackendstatus.py

diff --git a/.gitignore b/.gitignore
index 82495e8692..06875abebd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -58,6 +58,7 @@
 /configure.lineno
 /conftest.*
 /docs/aclperms.htmlinc
+/docs/storagebackendstatus.htmlinc
 /docs/apibuild.py.stamp
 /docs/devhelp/libvirt.devhelp
 /docs/hvsupport.html.in
diff --git a/docs/Makefile.am b/docs/Makefile.am
index 1cdb584b0b..526821b1d3 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -195,6 +195,7 @@ EXTRA_DIST= \
   $(kbase_html_in) $(kbase_html) \
   aclperms.htmlinc \
   hvsupport.pl \
+  storagebackendstatus.py \
   $(schema_DATA)
 
 acl_generated = aclperms.htmlinc
@@ -209,7 +210,8 @@ MAINTAINERCLEANFILES = \
   $(addprefix $(srcdir)/,$(devhelphtml)) \
   $(addprefix $(srcdir)/,$(internals_html)) \
   $(addprefix $(srcdir)/,$(kbase_html)) \
-  $(srcdir)/hvsupport.html.in $(srcdir)/aclperms.htmlinc
+  $(srcdir)/hvsupport.html.in $(srcdir)/aclperms.htmlinc \
+  $(srcdir)/storagebackendstatus.htmlinc
 
 timestamp="$(shell if test -n "$$SOURCE_DATE_EPOCH"; \
 		   then \
@@ -230,6 +232,9 @@ web: $(dot_html) $(internals_html) $(kbase_html) \
 
 hvsupport.html: $(srcdir)/hvsupport.html.in
 
+storagebackendstatus.htmlinc: $(srcdir)/storagebackendstatus.py
+	$(PYTHON) $< >$@
+
 $(srcdir)/hvsupport.html.in: $(srcdir)/hvsupport.pl $(api_DATA) \
 		$(top_srcdir)/src/libvirt_public.syms \
 	$(top_srcdir)/src/libvirt_qemu.syms $(top_srcdir)/src/libvirt_lxc.syms \
@@ -256,7 +261,7 @@ MAINTAINERCLEANFILES += \
 	convert -rotate 90 $< $@
 
 %.html.tmp: %.html.in site.xsl subsite.xsl page.xsl \
-		$(acl_generated)
+		$(acl_generated) storagebackendstatus.htmlinc
 	$(AM_V_GEN)name=`echo $@ | sed -e 's/.tmp//'`; \
 	  dir=`dirname $@` ; \
 	  if test "$$dir" = "."; \
diff --git a/docs/apibuild.py b/docs/apibuild.py
index dbdc1c95af..31944b8176 100755
--- a/docs/apibuild.py
+++ b/docs/apibuild.py
@@ -2010,6 +2010,8 @@ class docBuilder:
             self.includes = includes + list(lxc_included_files.keys())
         elif name == "libvirt-admin":
             self.includes = includes + list(admin_included_files.keys())
+        else:
+            self.includes = includes
         self.modules = {}
         self.headers = {}
         self.idx = index()
diff --git a/docs/storage.html.in b/docs/storage.html.in
index e0e4edec1e..2e4f662222 100644
--- a/docs/storage.html.in
+++ b/docs/storage.html.in
@@ -826,5 +826,19 @@
 
     <h3>Valid volume format types</h3>
     <p>The valid volume types are the same as for the directory pool.</p>
+
+    <h2>Storage Pool Types implementation status</h2>
+
+    <p>
+      The storage backends have different level of support of the various pool and volume actions.
+      Here is a matrix of the current support for each of them.
+    </p>
+
+    <p>
+      <strong>Note:</strong> some functions like Start and Stop will not trigger an exception when
+      called on a backend that doesn't implement them.
+    </p>
+
+    <div id="include" filename="storagebackendstatus.htmlinc"/>
   </body>
 </html>
diff --git a/docs/storagebackendstatus.py b/docs/storagebackendstatus.py
new file mode 100644
index 0000000000..d105fea626
--- /dev/null
+++ b/docs/storagebackendstatus.py
@@ -0,0 +1,64 @@
+import os
+import os.path
+import re
+
+srcdir = os.path.abspath((os.environ.get("srcdir", os.path.join("..", "src"))))
+
+def get_allowed_functions():
+    functions = []
+    with open(os.path.join(srcdir, 'storage', 'storage_backend.h'), 'r') as handle:
+        content = ''.join(handle.readlines())
+        definition = re.search('struct _virStorageBackend {([^}]+)}', content)
+        if definition is not None:
+            functions = re.findall('virStorageBackend[^ ]+ ([^;]+)', definition.group(1))
+    return functions
+
+class Backend:
+    def __init__(self, name, code):
+        self.name = name
+        self.functions = [member[1:] for member in re.findall('.([^ ]+) = ', code) if member != '.type']
+
+def get_backends():
+    backends = []
+    for root, dirs, files in os.walk(os.path.join(srcdir, 'storage')):
+        storage_impls = [os.path.join(root, f) for f in files if re.match('storage_backend_[^.]+.c', f)]
+        for impl in storage_impls:
+            handle = open(impl, 'r')
+            content = ''.join(handle.readlines())
+            handle.close()
+            chunks = re.findall('virStorageBackend virStorageBackend([^ ]+) = {([^}]*)}', content)
+            backends.extend([Backend(chunk[0], chunk[1]) for chunk in chunks])
+    return backends
+
+def main():
+    functions = get_allowed_functions()
+    backends = get_backends()
+
+    headers = '\n'.join(['<th>%s</th>' % backend.name for backend in backends])
+    rows = []
+    for func in functions:
+        cell_template = '<td style="text-align: center">%s</td>'
+        support = [cell_template % ('✔' if func in backend.functions else '') for backend in backends]
+        rows.append('\n'.join(['<tr>', '<td>%s</td>' % func] + support + ['</tr>']))
+
+    print('''<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<body>
+<table class='top_table'>
+<thead>
+<tr>
+<th>
+</th>
+%s
+</tr>
+</thead>
+<tbody>
+%s
+</tbody>
+</table>
+</body>
+</html>''' % (headers, '\n'.join(rows)))
+
+if __name__ == '__main__':
+    main()
-- 
2.22.0