[ADD] First implementation of base_trgm_search for creating indexes and allowing the sql parameter %.

base_trgm_search/__init__.py

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+# -*- coding: utf-8 -*-
+from . import models

base_trgm_search/__openerp__.py

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+# -*- coding: utf-8 -*-
+{
+    'name': "PostgreSQL Trigram Search",
+    'summary': """PostgreSQL Trigram Search""",
+    'category': 'Uncategorized',
+    'version': '8.0.1.0.0',
+    'website': 'https://odoo-community.org/',
+    'author': 'Daniel Reis, Odoo Community Association (OCA)',
+    'license': 'AGPL-3',
+    'depends': [
+        'base',
+    ],
+    'data': [
+        'views/trgm_index.xml',
+    ],
+    'installable': True,
+}

base_trgm_search/models/__init__.py

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+# -*- coding: utf-8 -*-
+from . import trgm_index

base_trgm_search/models/trgm_index.py

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+# -*- coding: utf-8 -*-
+import logging
+
+from openerp import api, exceptions, fields, models
+from openerp.osv import expression
+
+from psycopg2.extensions import AsIs
+
+_logger = logging.getLogger(__name__)
+
+
+class TrgmIndex(models.Model):
+
+    """Model for Trigram Index."""
+
+    _name = 'trgm.index'
+    _rec_name = 'field_id'
+
+    field_id = fields.Many2one(
+        comodel_name='ir.model.fields',
+        string='Field',
+        required=True,
+        help='You can either select a field of type "text" or "char".'
+    )
+
+    index_name = fields.Char(
+        string='Index Name',
+        readonly=True,
+        help='The index name is automatically generated like '
+             'fieldname_indextype_idx. If the index already exists and the '
+             'index is located in the same table then this index is resused. '
+             'If the index is located in another table then a number is added '
+             'at the end of the index name.'
+    )
+
+    index_type = fields.Selection(
+        selection=[('gin', 'GIN'), ('gist', 'GiST')],
+        string='Index Type',
+        default='gin',
+        required=True,
+        help='Cite from PostgreSQL documentation: "As a rule of thumb, a '
+             'GIN index is faster to search than a GiST index, but slower to '
+             'build or update; so GIN is better suited for static data and '
+             'GiST for often-updated data."'
+    )
+
+    @api.model
+    def _trgm_extension_exists(self):
+        self.env.cr.execute("""
+            SELECT name, installed_version
+            FROM pg_available_extensions
+            WHERE name = 'pg_trgm'
+            LIMIT 1;
+            """)
+
+        extension = self.env.cr.fetchone()
+        if extension is None:
+            return 'missing'
+
+        if extension[1] is None:
+            return 'uninstalled'
+
+        return 'installed'
+
+    @api.model
+    def _is_postgres_superuser(self):
+        self.env.cr.execute("SHOW is_superuser;")
+        superuser = self.env.cr.fetchone()
+        return superuser is not None and superuser[0] == 'on' or False
+
+    @api.model
+    def _install_trgm_extension(self):
+        extension = self._trgm_extension_exists()
+        if extension == 'missing':
+            _logger.warning('To use pg_trgm you have to install the '
+                            'postgres-contrib module.')
+        elif extension == 'uninstalled':
+            if self._is_postgres_superuser():
+                self.env.cr.execute("CREATE EXTENSION IF NOT EXISTS pg_trgm;")
+                return True
+            else:
+                _logger.warning('To use pg_trgm you have to create the '
+                                'extension pg_trgm in your database or you '
+                                'have to be the superuser.')
+        else:
+            return True
+        return False
+
+    @api.model
+    def _auto_init(self):
+        res = super(TrgmIndex, self)._auto_init()
+        self._install_trgm_extension()
+        return res
+
+    @api.model
+    def get_not_used_index(self, index_name, table_name, inc=1):
+        if inc > 1:
+            new_index_name = index_name + str(inc)
+        else:
+            new_index_name = index_name
+        self.env.cr.execute("""
+            SELECT tablename, indexname
+            FROM pg_indexes
+            WHERE indexname = %(index)s;
+            """, {'index': new_index_name})
+
+        indexes = self.env.cr.fetchone()
+        if indexes is not None and indexes[0] == table_name:
+            return True, index_name
+        elif indexes is not None:
+            return self.get_not_used_index(index_name, table_name,
+                                           inc + 1)
+
+        return False, new_index_name
+
+    @api.multi
+    def create_index(self):
+        self.ensure_one()
+
+        if not self._install_trgm_extension():
+            raise exceptions.UserError(
+                'The pg_trgm extension does not exists or cannot be '
+                'installed.')
+
+        table_name = self.env[self.field_id.model_id.model]._table
+        column_name = self.field_id.name
+        index_type = self.index_type
+        index_name = '%s_%s_idx' % (column_name, index_type)
+        index_exists, index_name = self.get_not_used_index(
+            index_name, table_name)
+
+        if not index_exists:
+            self.env.cr.execute("""
+            CREATE INDEX %(index)s
+            ON %(table)s
+            USING %(indextype)s (%(column)s %(indextype)s_trgm_ops);
+            """, {
+                'table': AsIs(table_name),
+                'index': AsIs(index_name),
+                'column': AsIs(column_name),
+                'indextype': AsIs(index_type)
+            })
+        return index_name
+
+    @api.model
+    def index_exists(self, model_name, field_name):
+        field = self.env['ir.model.fields'].search([
+            ('model', '=', model_name), ('name', '=', field_name)], limit=1)
+
+        if not field:
+            return False
+
+        trgm_index = self.search([('field_id', '=', field.id)], limit=1)
+        return bool(trgm_index)
+
+    @api.model
+    def create(self, vals):
+        rec = super(TrgmIndex, self).create(vals)
+        rec.index_name = rec.create_index()
+        return rec
+
+    @api.multi
+    def unlink(self):
+        for rec in self:
+            self.env.cr.execute("""
+                DROP INDEX IF EXISTS %(index)s;
+                """, {
+                'index': AsIs(rec.index_name),
+            })
+        return super(TrgmIndex, self).unlink()
+
+
+def patch_leaf_trgm(method):
+    def decorate_leaf_to_sql(self, eleaf):
+        model = eleaf.model
+        leaf = eleaf.leaf
+        left, operator, right = leaf
+        table_alias = '"%s"' % (eleaf.generate_alias())
+
+        if operator == '%':
+            sql_operator = '%%'
+            params = []
+
+            if left in model._columns:
+                format = model._columns[left]._symbol_set[0]
+                column = '%s.%s' % (table_alias, expression._quote(left))
+                query = '(%s %s %s)' % (column, sql_operator, format)
+            elif left in expression.MAGIC_COLUMNS:
+                query = "(%s.\"%s\" %s %%s)" % (
+                    table_alias, left, sql_operator)
+                params = right
+            else:  # Must not happen
+                raise ValueError(
+                    "Invalid field %r in domain term %r" % (left, leaf))
+
+            if left in model._columns:
+                params = model._columns[left]._symbol_set[1](right)
+
+            if isinstance(params, basestring):
+                params = [params]
+            return query, params
+        elif operator == 'inselect':
+            right = (right[0].replace(' % ', ' %% '), right[1])
+            eleaf.leaf = (left, operator, right)
+        return method(self, eleaf)
+    return decorate_leaf_to_sql
+expression.expression._expression__leaf_to_sql = patch_leaf_trgm(
+    expression.expression._expression__leaf_to_sql)
+expression.TERM_OPERATORS += ('%',)

base_trgm_search/views/trgm_index.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<openerp>
+  <data>
+
+    <record model="ir.ui.view" id="trgm_index_view_form">
+      <field name="name">trgm.index.view.form</field>
+      <field name="model">trgm.index</field>
+      <field name="arch" type="xml">
+        <form string="Trigam Index">
+          <sheet>
+            <group col="4">
+              <field name="field_id" domain="[('ttype', 'in', ['char', 'text'])]"/>
+              <field name="index_name"/>
+              <field name="index_type"/>
+            </group>
+          </sheet>
+        </form>
+      </field>
+    </record>
+
+    <record model="ir.ui.view" id="trgm_index_view_tree">
+      <field name="name">trgm.index.view.tree</field>
+      <field name="model">trgm.index</field>
+      <field name="arch" type="xml">
+        <tree string="Trigam Index">
+          <field name="field_id"/>
+          <field name="index_name"/>
+          <field name="index_type"/>
+        </tree>
+      </field>
+    </record>
+
+    <record model="ir.actions.act_window" id="trgm_index_action">
+      <field name="name">Trigam Index</field>
+      <field name="res_model">trgm.index</field>
+      <field name="view_type">form</field>
+      <field name="view_mode">tree,form</field>
+      <field name="type">ir.actions.act_window</field>
+    </record>
+
+    <menuitem id="trgm_index_menu"
+              parent="base.next_id_9"
+              action="trgm_index_action"/>
+
+  </data>
+</openerp>