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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 2/8] libxl/gentypes.py: don't generate default values
If a field:
0. is not of aggregate type
and
1. is of array type and the array is not empty
or 2. is of a type which has init_val and has been set to init_val,
or 3. is of builtin type and has been set to internal default value,
or 4. is of a type which has no init_val and has been set to 0
then there's no need to generate output for that field in JSON
output.
Note that 0 can result in output like
{
...
FOO : { }
...
}
where FOO is aggregate type but all its fields are set to default, hence
no JSON output in {} at all. This is not pretty, but it's still valid
JSON. And the parser should be able to skip touching those fields in the
resulting C structures. When the parser consumes that generated JSON
object, all default values should be automatically filled in.
Also change some non-zero init_vals to LIBXL_* for better readability in
generated C code.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
tools/libxl/gentypes.py | 33 +++++++++++++++++++++++++++++++--
tools/libxl/idl.py | 2 ++
tools/libxl/idl.txt | 9 +++++++++
tools/libxl/libxl_types.idl | 29 +++++++++++++++++------------
4 files changed, 59 insertions(+), 14 deletions(-)
diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py
index 01416e7..f06afd9 100644
--- a/tools/libxl/gentypes.py
+++ b/tools/libxl/gentypes.py
@@ -206,6 +206,29 @@ def libxl_C_type_gen_map_key(f, parent, indent = ""):
s = indent + s
return s.replace("\n", "\n%s" % indent).rstrip(indent)
+def get_init_val(f):
+ if f.init_val is not None:
+ return f.init_val
+ elif f.type.init_val is not None:
+ return f.type.init_val
+ return None
+
+def get_default_expr(f, nparent, fexpr):
+ if isinstance(f.type, idl.Aggregate):
+ return "1 /* always generate JSON output for aggregate type */"
+
+ if isinstance(f.type, idl.Array):
+ return "%s && %s" % (fexpr, nparent + f.type.lenvar.name)
+
+ init_val = get_init_val(f)
+ if init_val is not None:
+ return "%s != %s" % (fexpr, init_val)
+
+ if f.type.check_default_fn:
+ return "!%s(&%s)" % (f.type.check_default_fn, fexpr)
+
+ return "%s" % fexpr
+
def libxl_C_type_gen_json(ty, v, indent = " ", parent = None):
s = ""
if parent is None:
@@ -255,8 +278,14 @@ def libxl_C_type_gen_json(ty, v, indent = " ", parent =
None):
s += " goto out;\n"
for f in [f for f in ty.fields if not f.const and not f.type.private]:
(nparent,fexpr) = ty.member(v, f, parent is None)
- s += libxl_C_type_gen_map_key(f, nparent)
- s += libxl_C_type_gen_json(f.type, fexpr, "", nparent)
+ default_expr = get_default_expr(f, nparent, fexpr)
+ s += "if (%s) {\n" % default_expr
+
+ s += libxl_C_type_gen_map_key(f, nparent, " ")
+ s += libxl_C_type_gen_json(f.type, fexpr, " ", nparent)
+
+ s += "}\n"
+
s += "s = yajl_gen_map_close(hand);\n"
s += "if (s != yajl_gen_status_ok)\n"
s += " goto out;\n"
diff --git a/tools/libxl/idl.py b/tools/libxl/idl.py
index 8b118dd..ada801a 100644
--- a/tools/libxl/idl.py
+++ b/tools/libxl/idl.py
@@ -64,6 +64,8 @@ class Type(object):
self.init_val = kwargs.setdefault('init_val', None)
self.autogenerate_init_fn = kwargs.setdefault('autogenerate_init_fn',
False)
+ self.check_default_fn = kwargs.setdefault('check_default_fn', None)
+
if self.typename is not None and not self.private:
self.json_gen_fn = kwargs.setdefault('json_gen_fn', self.typename
+ "_gen_json")
else:
diff --git a/tools/libxl/idl.txt b/tools/libxl/idl.txt
index 6a53dd8..d47eba8 100644
--- a/tools/libxl/idl.txt
+++ b/tools/libxl/idl.txt
@@ -69,6 +69,15 @@ Type.autogenerate_json: (default: True)
Indicates if the above named Type.json_gen_fn should be autogenerated.
+Type.check_default_fn:
+
+ If it's set then calling this function shall return true if this type
+ has been set to default value (internal libxl implementation).
+
+ If this is not set, that means we can check the type against init_val
+ (if it has one) or zero to determine whether the value is default
+ value.
+
Other simple type-Classes
-------------------------
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 1018142..7234519 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -5,18 +5,23 @@
namespace("libxl_")
-libxl_defbool = Builtin("defbool", passby=PASS_BY_REFERENCE)
+libxl_defbool = Builtin("defbool", passby=PASS_BY_REFERENCE,
check_default_fn="libxl__defbool_is_default")
libxl_domid = Builtin("domid", json_gen_fn = "yajl_gen_integer",
autogenerate_json = False)
libxl_devid = Builtin("devid", json_gen_fn = "yajl_gen_integer",
autogenerate_json = False, signed = True, init_val="-1")
-libxl_uuid = Builtin("uuid", passby=PASS_BY_REFERENCE)
-libxl_mac = Builtin("mac", passby=PASS_BY_REFERENCE)
-libxl_bitmap = Builtin("bitmap", dispose_fn="libxl_bitmap_dispose",
passby=PASS_BY_REFERENCE)
-libxl_cpuid_policy_list = Builtin("cpuid_policy_list",
dispose_fn="libxl_cpuid_dispose", passby=PASS_BY_REFERENCE)
-
-libxl_string_list = Builtin("string_list",
dispose_fn="libxl_string_list_dispose", passby=PASS_BY_REFERENCE)
-libxl_key_value_list = Builtin("key_value_list",
dispose_fn="libxl_key_value_list_dispose", passby=PASS_BY_REFERENCE)
-libxl_hwcap = Builtin("hwcap", passby=PASS_BY_REFERENCE)
+libxl_uuid = Builtin("uuid", passby=PASS_BY_REFERENCE,
check_default_fn="libxl_uuid_is_nil")
+libxl_mac = Builtin("mac", passby=PASS_BY_REFERENCE,
check_default_fn="libxl__mac_is_default")
+libxl_bitmap = Builtin("bitmap", dispose_fn="libxl_bitmap_dispose",
passby=PASS_BY_REFERENCE,
+ check_default_fn="libxl_bitmap_is_empty")
+libxl_cpuid_policy_list = Builtin("cpuid_policy_list",
dispose_fn="libxl_cpuid_dispose", passby=PASS_BY_REFERENCE,
+
check_default_fn="libxl__cpuid_policy_is_empty")
+
+libxl_string_list = Builtin("string_list",
dispose_fn="libxl_string_list_dispose", passby=PASS_BY_REFERENCE,
+ check_default_fn="libxl__string_list_is_empty")
+libxl_key_value_list = Builtin("key_value_list",
dispose_fn="libxl_key_value_list_dispose", passby=PASS_BY_REFERENCE,
+
check_default_fn="libxl__key_value_list_is_empty")
+libxl_hwcap = Builtin("hwcap", passby=PASS_BY_REFERENCE,
+ check_default_fn="libxl__hwcap_is_default")
#
# Specific integer types
@@ -49,7 +54,7 @@ libxl_domain_type = Enumeration("domain_type", [
(-1, "INVALID"),
(1, "HVM"),
(2, "PV"),
- ], init_val = -1)
+ ], init_val = "LIBXL_DOMAIN_TYPE_INVALID")
libxl_device_model_version = Enumeration("device_model_version", [
(0, "UNKNOWN"),
@@ -95,7 +100,7 @@ libxl_action_on_shutdown = Enumeration("action_on_shutdown",
[
(5, "COREDUMP_DESTROY"),
(6, "COREDUMP_RESTART"),
- ], init_val = 1)
+ ], init_val = "LIBXL_ACTION_ON_SHUTDOWN_DESTROY")
libxl_trigger = Enumeration("trigger", [
(0, "UNKNOWN"),
@@ -154,7 +159,7 @@ libxl_vga_interface_type =
Enumeration("vga_interface_type", [
(1, "CIRRUS"),
(2, "STD"),
(3, "NONE"),
- ], init_val = 1)
+ ], init_val = "LIBXL_VGA_INTERFACE_TYPE_CIRRUS")
libxl_vendor_device = Enumeration("vendor_device", [
(0, "NONE"),
--
1.7.10.4
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