rapidyaml_support.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright (C) 2020  The SymbiFlow Authors.
#
# Use of this source code is governed by a ISC-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/ISC
#
# SPDX-License-Identifier: ISC
""" Implements YAML text format support using RapidYaml library. """
from fpga_interchange.converters import AbstractWriter, AbstractReader, \
        to_writer, from_reader, SCALAR_TYPES
import ryml
from ryml import Tree

CHECK_TREE = True


class YamlReference():
    def __init__(self, ref):
        self.ref = ref


def mkvalue(v):
    if v is True:
        return 'true'
    elif v is False:
        return 'false'
    elif v is None:
        return 'null'
    else:
        return str(v)


def set_key_val_ref(tree, mkstr, keyval_id, key, ref):
    assert isinstance(ref, YamlReference)
    # FIXME: Bug in RapidYaml requires setting the value to also be the ref
    # string.
    tree.to_keyval(keyval_id, mkstr(key), mkstr('*' + ref.ref))
    tree.set_val_ref(keyval_id, ref.ref)


def set_val_ref(tree, mkstr, val_id, ref):
    assert isinstance(ref, YamlReference)
    # FIXME: Bug in RapidYaml requires setting the value to also be the ref
    # string.
    tree.to_val(val_id, mkstr('*' + ref.ref))
    tree.set_val_ref(val_id, ref.ref)


class RapidYamlWriter(AbstractWriter):
    def __init__(self, struct_reader, parent):
        super().__init__(struct_reader, parent)

        if parent is None:
            self.tree = Tree()
            self.tree.reserve(16)
            self.id = self.tree.root_id()
            self.strings = []
            self.tree.to_map(self.id)
            self.nursery_id = self.tree.append_child(self.id)
            self.tree.to_seq(self.nursery_id)
        else:
            self.tree = parent.tree
            self.nursery_id = parent.nursery_id
            self.id = self.tree.append_child(self.nursery_id)
            self.strings = parent.strings
            self.tree.to_map(self.id)

        self.field_ids = {}
        self.list_ids = {}
        self.struct_reader = struct_reader
        self.parent = parent
        self.ref_index = 1

    def mkstr(self, s):
        self.strings.append(s)
        return self.strings[-1]

    def make_reference(self, ref_id):
        if self.tree.is_anchor(ref_id):
            return YamlReference(
                self.mkstr(
                    bytes(self.tree.val_anchor(ref_id)).decode('utf-8')))
        else:
            ref = self.mkstr('id{:03d}'.format(self.ref_index))
            self.ref_index += 1

            self.tree.set_val_anchor(ref_id, ref)
            return YamlReference(ref)

    def get_list_id(self, field, index):
        field_id = self.field_ids[field]
        if field_id not in self.list_ids:
            l = []
            for value_id in ryml.children(self.tree, field_id):
                l.append(value_id)
            self.list_ids[field_id] = l

        return self.list_ids[field_id][index]

    def dereference_value(self, annotation_type, value, root_writer,
                          parent_writer):
        if annotation_type.type == 'root':
            ref_id = root_writer.get_list_id(annotation_type.field, value)
            return root_writer.make_reference(ref_id)

        elif annotation_type.type == 'rootValue':
            return root_writer.get_field_value(annotation_type.field, value)
        else:
            assert annotation_type.type == 'parent'
            parent = self.get_parent(annotation_type.depth)
            ref_id = parent.get_list_id(annotation_type.field, value)

            assert ref_id != ryml.NONE
            assert not self.tree.has_key(ref_id)

            return root_writer.make_reference(ref_id)

    def set_value(self, key, value_which, value):
        if isinstance(value, YamlReference):
            keyval_id = self.tree.append_child(self.id)
            set_key_val_ref(self.tree, self.mkstr, keyval_id, key, value)
            return

        if value_which in SCALAR_TYPES:
            keyval_id = self.tree.append_child(self.id)
            self.field_ids[key] = keyval_id
            self.tree.to_keyval(keyval_id, self.mkstr(key),
                                self.mkstr(mkvalue(value)))
        elif value_which == 'list':
            list_id = value
            assert self.tree.parent(list_id) == self.id
            self.field_ids[key] = list_id
            self.tree._set_key(list_id, self.mkstr(key))
        elif value_which == 'void':
            keyval_id = self.tree.append_child(self.id)
            self.field_ids[key] = keyval_id
            self.tree.to_keyval(keyval_id, self.mkstr(key), self.mkstr('null'))
        elif value_which == 'enum':
            keyval_id = self.tree.append_child(self.id)
            self.field_ids[key] = keyval_id
            self.tree.to_keyval(keyval_id, self.mkstr(key), self.mkstr(value))
        elif value_which == 'struct':
            assert value != ryml.NONE
            assert self.tree.parent(value) == self.nursery_id
            assert self.tree.is_map(value)
            self.tree.move(value, self.id, self.tree.last_child(self.id))
            self.tree._set_key(value, self.mkstr(key))
            self.field_ids[key] = value
        else:
            assert False, value_which

    def set_value_inner_key(self, key, inner_key, value_which, value):
        outer_id = self.tree.append_child(self.id)
        self.tree.to_map(outer_id, self.mkstr(key))

        if isinstance(value, YamlReference):
            keyval_id = self.tree.append_child(outer_id)
            set_key_val_ref(self.tree, self.mkstr, keyval_id, inner_key, value)
            return

        if value_which in SCALAR_TYPES:
            keyval_id = self.tree.append_child(outer_id)
            self.tree.to_keyval(keyval_id, self.mkstr(inner_key),
                                self.mkstr(mkvalue(value)))
        elif value_which == 'list':
            list_id = value
            assert list_id != ryml.NONE
            assert self.tree.parent(list_id) == self.id
            self.tree.move(list_id, outer_id, ryml.NONE)
            self.tree._set_key(list_id, self.mkstr(inner_key))

            assert self.tree.parent(list_id) == outer_id
            assert self.tree.num_children(outer_id) == 1
            assert self.tree.first_child(outer_id) == list_id

        elif value_which == 'void':
            keyval_id = self.tree.append_child(outer_id)
            self.tree.to_keyval(keyval_id, self.mkstr(inner_key),
                                self.mkstr('null'))
        elif value_which == 'enum':
            keyval_id = self.tree.append_child(outer_id)
            self.tree.to_keyval(keyval_id, self.mkstr(inner_key),
                                self.mkstr(value))
        elif value_which == 'struct':
            assert value != ryml.NONE
            assert self.tree.parent(value) == self.nursery_id
            assert self.tree.is_map(value)

            self.tree.move(value, outer_id, ryml.NONE)
            self.tree._set_key(value, self.mkstr(inner_key))

            assert self.tree.parent(value) == outer_id
            assert self.tree.num_children(outer_id) == 1
            assert self.tree.first_child(outer_id) == value
        else:
            assert False, value_which

    def make_list(self):
        list_id = self.tree.append_child(self.id)
        self.tree.to_seq(list_id)
        return list_id

    def append_to_list(self, list_id, value_which, value):
        if isinstance(value, YamlReference):
            val_id = self.tree.append_child(list_id)
            set_val_ref(self.tree, self.mkstr, val_id, value)
            return

        if value_which == 'struct':
            assert self.tree.parent(value) == self.nursery_id
            assert self.tree.is_map(value)

            self.tree.move(value, list_id, self.tree.last_child(list_id))

            assert self.tree.parent(value) == list_id
        else:
            assert value_which in SCALAR_TYPES
            val_id = self.tree.append_child(list_id)
            self.tree.to_val(val_id, self.mkstr(mkvalue(value)))

    def output(self):
        if self.parent is None:
            if CHECK_TREE:
                seen_nodes = set()
                for node, il in ryml.walk(self.tree):
                    assert node not in seen_nodes, (node, il)
                    seen_nodes.add(node)

            assert self.tree.num_children(self.nursery_id) == 0
            self.tree.remove(self.nursery_id)

            return self.strings, self.tree
        else:
            return self.id


def handle_value(s):
    if s is None:
        return s
    else:
        return bytes(s).decode('utf-8')


def get_value(tree, field_id):
    if tree.is_val_ref(field_id):
        return YamlReference(bytes(tree.val_ref(field_id)).decode('utf-8'))

    if tree.is_map(field_id):
        return field_id
    elif tree.is_seq(field_id):
        value_id = tree.first_child(field_id)
        if value_id == ryml.NONE:
            return []

        assert not tree.is_seq(value_id)
        if tree.is_map(value_id):
            return list(ryml.children(tree, field_id))
        else:
            out = []
            for value_id in ryml.children(tree, field_id):
                if tree.is_val_ref(value_id):
                    out.append(
                        YamlReference(
                            bytes(tree.val_ref(value_id)).decode('utf-8')))
                else:
                    s = handle_value(tree.val(value_id))
                    out.append(s)
            return out
    else:
        s = handle_value(tree.val(field_id))
        return s


class RapidYamlReader(AbstractReader):
    def __init__(self, data, parent):
        super().__init__(data, parent)

        self.parent = parent
        if self.parent is None:
            self.tree = data
            self.id = self.tree.root_id()
        else:
            self.tree = parent.tree
            self.id = data

        self.field_ids = {}
        self.field_refs = {}

    def _init_fields(self):
        if len(self.field_ids) > 0:
            return

        assert self.tree.is_map(self.id)

        for field_id in ryml.children(self.tree, self.id):
            field_key = bytes(self.tree.key(field_id)).decode('utf-8')

            assert field_key not in self.field_ids
            self.field_ids[field_key] = field_id

    def find_ref_index(self, field, target_ref):
        self._init_fields()

        if field not in self.field_refs:
            field_id = self.field_ids[field]
            self.field_refs[field] = {}
            for idx, value_id in enumerate(ryml.children(self.tree, field_id)):
                if self.tree.is_anchor(value_id):
                    ref = bytes(self.tree.val_anchor(value_id)).decode('utf-8')
                    assert ref not in self.field_refs[field]
                    self.field_refs[field][ref] = idx

        return self.field_refs[field][target_ref]

    def read_scalar(self, field_which, field_data):
        if field_which == 'text':
            return field_data
        elif field_which == 'bool':
            if field_data == True:
                return True
            elif field_data == False:
                return False
            elif field_data == 'true':
                return True
            elif field_data == 'false':
                return False
            else:
                assert False, field_data
        elif field_which == 'float32' and field_which == 'float64':
            return float(field_data)
        else:
            return int(field_data)

    def reference_value(self, annotation_type, value, root_reader,
                        parent_reader):
        if annotation_type.type == 'root':
            assert isinstance(value, YamlReference)
            return root_reader.find_ref_index(annotation_type.field, value.ref)
        elif annotation_type.type == 'rootValue':
            return root_reader.get_object(
                annotation_type.field).get_index(value)
        else:
            assert annotation_type.type == 'parent'
            assert isinstance(value, YamlReference)
            return self.get_parent(annotation_type.depth).find_ref_index(
                annotation_type.field, value.ref)

    def keys(self):
        self._init_fields()
        return self.field_ids.keys()

    def get_field_keys(self, key):
        self._init_fields()
        outer_id = self.field_ids[key]
        assert self.tree.num_children(outer_id) == 1
        field_id = self.tree.first_child(outer_id)
        return {bytes(self.tree.key(field_id)).decode('utf-8'): None}.keys()

    def get_inner_field(self, key, inner_key):
        self._init_fields()
        outer_id = self.field_ids[key]
        assert self.tree.num_children(outer_id) == 1
        field_id = self.tree.first_child(outer_id)

        return get_value(self.tree, field_id)

    def get_field(self, key):
        self._init_fields()
        field_id = self.field_ids[key]

        return get_value(self.tree, field_id)


def to_rapidyaml(struct_reader):
    """ Converts struct_reader to ryml.Tree object.

    Because ryml.Tree doesn't hold string values, this function returns
    two objects.  The first is the list of all strings in the ryml.Tree.
    This objects lifetime must exceed the ryml.Tree's lifetime.

    Returns:
        - List of strings used in ryml.Tree
        - ryml.Tree object.
    """
    return to_writer(struct_reader, RapidYamlWriter)


def from_rapidyaml(message, data):
    """ Converts ryml.Tree object to a FPGA interchange message. """
    from_reader(message, data, RapidYamlReader)