Project

General

Profile

1 13 aaronmk
# XML-database conversion
2
3 2418 aaronmk
import copy
4 16 aaronmk
import re
5 13 aaronmk
from xml.dom import Node
6
7 3718 aaronmk
import dicts
8 446 aaronmk
import exc
9 2436 aaronmk
import Parser
10 46 aaronmk
import sql
11 3077 aaronmk
import sql_io
12 2268 aaronmk
import sql_gen
13 84 aaronmk
import strings
14 133 aaronmk
import util
15 46 aaronmk
import xml_dom
16 2113 aaronmk
import xml_func
17 2436 aaronmk
import xpath
18 13 aaronmk
19 139 aaronmk
def name_of(node): return re.sub(r'^.*\.', r'', node.tagName)
20 16 aaronmk
21 13 aaronmk
ptr_suffix = '_id'
22
23 138 aaronmk
def is_ptr(node_name): return node_name.lower().endswith(ptr_suffix)
24 13 aaronmk
25 172 aaronmk
def ptr_type_guess(node_name):
26 13 aaronmk
    assert is_ptr(node_name)
27
    return node_name[:-len(ptr_suffix)]
28
29
def ptr_target(node):
30
    assert is_ptr(name_of(node))
31 2113 aaronmk
    return xml_dom.value_node(node)
32 13 aaronmk
33
def find_by_name(node, name):
34 46 aaronmk
    for parent in xml_dom.NodeParentIter(node):
35 13 aaronmk
        if name_of(parent) == name: return parent
36
        else:
37 46 aaronmk
            for child in xml_dom.NodeElemIter(parent):
38 16 aaronmk
                child_name = name_of(child)
39 13 aaronmk
                if is_ptr(child_name):
40 172 aaronmk
                    target = ptr_target(child)
41
                    if target.tagName == name: return target
42 13 aaronmk
                elif child_name == name: return child
43
    return None
44
45 2039 aaronmk
class ColRef:
46
    '''A reference to a table column'''
47
    def __init__(self, name, idx):
48
        self.name = name
49
        self.idx = idx
50
51
    def __str__(self): return self.name
52
53 4242 aaronmk
input_col_prefix = xml_func.var_name_prefix
54 4241 aaronmk
55 3652 aaronmk
put_special_funcs = set(['_simplifyPath'])
56 2549 aaronmk
57 3660 aaronmk
def put(db, node, row_ins_ct_ref=None, on_error=exc.reraise,
58 3649 aaronmk
    col_defaults={}, in_table=None, parent_ids_loc=None, next=None):
59 3676 aaronmk
    '''
60
    @param node To use an entire XML document, pass root.firstChild.
61
    '''
62
    if node == None: return None # when no rows, root.firstChild == None
63
64 3685 aaronmk
    def put_(node):
65
        return put(db, node, row_ins_ct_ref, on_error, col_defaults, in_table,
66
            parent_ids_loc, next)
67 3621 aaronmk
68 4491 aaronmk
    def augment_error(e): exc.add_msg(e, 'node:\n'+strings.ustr(node))
69 3646 aaronmk
    def on_error_(e):
70 3677 aaronmk
        augment_error(e)
71 3646 aaronmk
        on_error(e)
72
73 3719 aaronmk
    def wrap_e(e):
74
        augment_error(e)
75
        raise xml_func.SyntaxError(e)
76 3718 aaronmk
77 2551 aaronmk
    is_func = xml_func.is_func(node)
78 2005 aaronmk
    out_table = name_of(node)
79 2432 aaronmk
80
    # Divide children into fields and children with fkeys to parent
81 3718 aaronmk
    row = dicts.OnceOnlyDict()
82 2005 aaronmk
    children = []
83 3718 aaronmk
    try:
84
        for child in xml_dom.NodeElemIter(node):
85
            child_name = name_of(child)
86
            if xml_dom.is_empty(child): row[child_name] = None
87
            elif xml_dom.is_text(child):
88
                row[child_name] = strings.to_unicode(xml_dom.value(child))
89
            else:
90
                child_value = xml_dom.value_node(child)
91
                if (is_func or is_ptr(child_name)
92
                    or xml_func.is_func(child_value)):
93
                    row[child_name] = child_value
94
                else: children.append(child)
95
    except dicts.KeyExistsError, e: wrap_e(e)
96 2434 aaronmk
97
    # Special handling for structural XML functions
98
    if out_table == '_simplifyPath':
99 2436 aaronmk
        # Parse args
100 2434 aaronmk
        try:
101 3650 aaronmk
            next = row['next'] # modifies outer next var used by put_()
102 2434 aaronmk
            path = row['path']
103 2436 aaronmk
        except KeyError, e: wrap_e(e)
104
        try: next = xpath.parse(next)
105
        except Parser.SyntaxError, e: wrap_e(e)
106
        try: next = next[0].name
107
        except IndexError, e: wrap_e(e)
108 2434 aaronmk
109 3650 aaronmk
        return put_(path)
110 2434 aaronmk
111 3687 aaronmk
    is_literals = in_table == None
112 3624 aaronmk
    in_tables = []
113
    no_empty = set()
114 3687 aaronmk
    if not is_literals:
115 3624 aaronmk
        in_tables.append(in_table)
116
        no_empty.add(in_table)
117 2966 aaronmk
118 3107 aaronmk
    def pkey(table): return sql.pkey(db, table, True)
119
120 2177 aaronmk
    # Add fkey to parent
121
    if parent_ids_loc != None:
122 3601 aaronmk
        if sql_gen.is_table_col(parent_ids_loc):
123
            no_empty.add(parent_ids_loc.table)
124 2177 aaronmk
        parent_ptr = node.getAttribute('fkey')
125
        if parent_ptr == '': parent_ptr = pkey(name_of(node.parentNode))
126
        row[parent_ptr] = parent_ids_loc
127
128 5071 aaronmk
    # Parse input columns
129 3718 aaronmk
    row = row.inner # now allow keys to be overwritten
130 2060 aaronmk
    for out_col, value in row.iteritems():
131 5071 aaronmk
        if (not is_literals and util.is_str(value)
132
            and value.startswith(input_col_prefix)): # value is input column
133
            row[out_col] = sql_gen.Col(strings.remove_prefix(input_col_prefix,
134
                value), in_table)
135
136 5075 aaronmk
    # Optimizations for structural XML functions
137
    if out_table == '_alt': # return first arg if non-NULL
138
        args = row.items()
139
        args.sort()
140
        out_col, value = min(args) # first arg
141
        if xml_dom.is_node(value): row[out_col] = value = put_(value)
142
        if not sql_gen.is_nullable(db, value): return value
143
144 5071 aaronmk
    # Process values
145
    parent_ids_loc = None # applies to this section
146
    for out_col, value in row.iteritems():
147 2432 aaronmk
        # Handle forward pointers
148 3650 aaronmk
        if xml_dom.is_node(value): row[out_col] = value = put_(value)
149 2432 aaronmk
150
        # Translate values
151 5071 aaronmk
        if isinstance(value, sql_gen.Col): # value is table column
152 3687 aaronmk
            assert sql_gen.is_table_col(value)
153 5071 aaronmk
            if value.table is not in_table: in_tables.append(value.table)
154 3428 aaronmk
        else: # value is literal value
155 2323 aaronmk
            row[out_col] = sql_gen.NamedCol(out_col, value)
156 2060 aaronmk
157
    # Insert node
158 3657 aaronmk
    try: pkeys_loc = sql_io.put_table(db, out_table, in_tables, row,
159
        row_ins_ct_ref, next, col_defaults, on_error_)
160
    except Exception, e:
161 3677 aaronmk
        augment_error(e)
162
        raise
163 5382 aaronmk
    if sql_gen.is_table_col(pkeys_loc): no_empty.add(pkeys_loc.table)
164 2060 aaronmk
165 2975 aaronmk
    sql.empty_temp(db, set(in_tables) - no_empty)
166 2966 aaronmk
167 2177 aaronmk
    # Insert children with fkeys to parent
168 2506 aaronmk
    parent_ids_loc = pkeys_loc # applies to this section
169 3650 aaronmk
    for child in children: put_(child)
170 2177 aaronmk
171 2133 aaronmk
    return pkeys_loc
172 3651 aaronmk
173
def get(db, node, limit=None, start=None):
174
    def pkey(table): return sql.pkey(db, table)
175
176
    node = node.firstChild
177
    table = name_of(node)
178
    pkey_ = pkey(table)
179
180
    fields = []
181
    conds = {}
182
    for child in xml_dom.NodeElemIter(node):
183
        child_name = name_of(child)
184
        if xml_dom.is_empty(child): fields.append(child_name)
185
        elif xml_dom.is_text(child): conds[child_name] = xml_dom.value(child)
186
        else: raise Exception('Joins not supported yet')
187
    id_ = xml_dom.get_id(node)
188
    if id_ != None: conds[pkey(table)] = id_ # replace any existing pkey value
189
    if fields == []: fields.append(pkey_)
190
191
    return sql.select(db, table, fields, conds, limit, start)
192
193
# Controls when and how put_table() will partition the input table
194
partition_size = 500000 # rows
195
196
def put_table(db, node, in_table, in_row_ct_ref=None, row_ins_ct_ref=None,
197 5007 aaronmk
    limit=None, start=0, on_error=exc.reraise, col_defaults={},
198
    partition_size=partition_size):
199 3651 aaronmk
    '''
200
    @param node The XML tree that transforms the input to the output. Similar to
201
        put()'s node param, but with the input column name prefixed by
202
        input_col_prefix in place of the column value.
203
    @return sql_gen.Col Where the pkeys (from INSERT RETURNING) are made
204
        available
205
    '''
206
    in_table = sql_gen.as_Table(in_table)
207 4437 aaronmk
    sql_io.mk_errors_table(db, in_table)
208 3651 aaronmk
    in_table.set_srcs([in_table], overwrite=False)
209 4491 aaronmk
    db.src = strings.ustr(in_table)
210 3651 aaronmk
211
    db.autoanalyze = True # but don't do this in row-based import
212
    db.autoexplain = True # but don't do this in row-based import
213
214
    # Subset and partition in_table
215
    # OK to do even if table already the right size because it takes <1 sec.
216
    full_in_table = in_table
217 5087 aaronmk
    pkeys_loc = None # used if loop is never executed
218 3651 aaronmk
    total = 0
219
    while limit == None or total < limit:
220
        # Adjust partition size if last partition
221
        this_limit = partition_size
222
        if limit != None: this_limit = min(this_limit, limit - total)
223
224
        # Row # is interally 0-based, but 1-based to the user
225
        db.log_debug('********** Partition: rows '+str(start+1)+'-'
226
            +str(start+this_limit)+' **********', level=1.2)
227
228
        # Subset in_table
229 5022 aaronmk
        in_table = sql_gen.Table(strings.ustr(full_in_table),
230
            srcs=full_in_table.srcs, is_temp=True) # prepend schema to name
231 5023 aaronmk
        sql.copy_table_struct(db, full_in_table, in_table)
232 5385 aaronmk
        try: sql.add_row_num(db, in_table, 'row_num')
233 5024 aaronmk
        except sql.DatabaseErrors: pass # already has pkey
234 5023 aaronmk
        cur = sql.insert_select(db, in_table, None, sql.mk_select(db,
235 5026 aaronmk
            full_in_table, limit=this_limit, start=start, order_by=None))
236 3651 aaronmk
237
        this_ct = cur.rowcount
238
        total += this_ct
239
        start += this_ct # advance start to fetch next set
240
        if this_ct == 0: break # in_table size is multiple of partition_size
241
242 5018 aaronmk
        # Import data
243
        pkeys_loc = put(db, node, row_ins_ct_ref, on_error, col_defaults,
244
            in_table)
245 3651 aaronmk
        if in_row_ct_ref != None: in_row_ct_ref[0] += this_ct
246
247
        sql.empty_temp(db, in_table)
248
249
        if this_ct < partition_size: break # partial partition = last
250
251
        # Work around PostgreSQL's temp table disk space leak
252
        db.reconnect()
253
254
    return pkeys_loc