[FIX] pos_cache: load products by batches

pos_cache is used to speed up opening POS in databases with large number of
products. In some cases it's still not enough and thousands of records cannot be
cached in a single request, because reading information may take more time than
maximum allowed.

As a workaround, this commit adds posibility to split request into few small
requests. To activate the feature set system parameter
``pos_cache.limit_products_per_request`` to appropriate value depending on your
server capacity.

---

opw-2439347

closes odoo/odoo#66539

Signed-off-by: pimodoo <pimodoo@users.noreply.github.com>

1 files changed, 46 insertions, 8 deletions

diff --git a/addons/pos_cache/static/src/js/pos_cache.js b/addons/pos_cache/static/src/js/pos_cache.js
index 4f840082fb1..48dfbd4a745 100644
--- a/addons/pos_cache/static/src/js/pos_cache.js
+++ b/addons/pos_cache/static/src/js/pos_cache.js
@@ -31,18 +31,56 @@ models.PosModel = models.PosModel.extend({
           // other modules) in js.
           var product_fields =  typeof self.product_model.fields === 'function'  ? self.product_model.fields(self)  : self.product_model.fields;
           var product_domain =  typeof self.product_model.domain === 'function'  ? self.product_model.domain(self)  : self.product_model.domain;
-            var records = rpc.query({
+            var limit_products_per_request = self.config.limit_products_per_request;
+            var cur_request = 0;
+            function next(resolve, reject){
+                var domain = product_domain;
+                if (limit_products_per_request){
+                    domain = domain.slice();
+                    // implement offset-limit via id, because "pos.cache"
+                    // doesn't have such fields and we can add them in master
+                    // branch only
+                    domain.unshift(['id', '>', cur_request * limit_products_per_request],
+                                   ['id', '<=', (cur_request + 1) * limit_products_per_request]);
+                }
+                return rpc.query({
                     model: 'pos.config',
                     method: 'get_products_from_cache',
-                    args: [self.pos_session.config_id[0], product_fields, product_domain],
+                    args: [self.pos_session.config_id[0], product_fields, domain],
+                }).then(function (products) {
+                    self.db.add_products(_.map(products, function (product) {
+                        product.categ = _.findWhere(self.product_categories, {'id': product.categ_id[0]});
+                        product.pos = self;
+                        return new models.Product({}, product);
+                    }));
+                    if (limit_products_per_request) {
+                        cur_request++;
+                        // check that we have more products
+                        domain = product_domain.slice();
+                        domain.unshift(['id', '>', cur_request * limit_products_per_request]);
+                        rpc.query({
+                            model: 'product.product',
+                            method: 'search_read',
+                            args: [domain, ['id']],
+                            kwargs: {
+                                limit: 1,
+                            }
+                        }).then(function (products) {
+                            if (products.length){
+                                next(resolve, reject);
+                            } else {
+                                resolve();
+                            }
+                        });
+                    } else {
+                        resolve();
+                    }
                 });
+            }
             self.setLoadingMessage(_t('Loading') + ' product.product', 1);
-            return records.then(function (products) {
-                self.db.add_products(_.map(products, function (product) {
-                    product.categ = _.findWhere(self.product_categories, {'id': product.categ_id[0]});
-                    product.pos = self;
-                    return new models.Product({}, product);
-                }));
+
+            return new Promise((resolve, reject) => {
+                next(resolve, reject);
             });
         });
     },