[sai-gen] Refactor the templates of libsai implementation (#648)

Base on #647, refactor the
templates of libsai implementation
to make it more readable and maintainable. It replaces one single
template `saiapi.cpp.j2` with several
small templates under directory `SAI/templates/impls`.

The changes will not change any generated cpp code for sai api
implementation:
```
junhuazhai@junhuazhai-dev-vm:~/workspace/DASH/dash-pipeline$ diff -Nur -x '*.[od]' ~/DASH/dash-pipeline/SAI/lib/ SAI/lib
junhuazhai@junhuazhai-dev-vm:~/workspace/DASH/dash-pipeline$
```

dash-pipeline/SAI/sai_api_gen.py

@@ -16,7 +16,7 @@
     from utils.dash_p4 import DashP4SAIExtensions
     from utils.p4ir import P4IRTree, P4VarRefGraph
     from utils.sai_spec import SaiSpec
-    from utils.sai_gen import SAIGenerator, SaiHeaderGenerator
+    from utils.sai_gen import SAIGenerator, SaiHeaderGenerator, SaiImplGenerator
 except ImportError as ie:
     print("Import failed for " + ie.name)
     exit(1)
@@ -75,3 +75,4 @@
     # Generate and update all SAI files
     SAIGenerator(dash_sai_exts).generate()
     SaiHeaderGenerator(sai_spec).generate()
+    SaiImplGenerator(sai_spec).generate()

dash-pipeline/SAI/templates/impls/p4_table_action.cpp.j2

@@ -0,0 +1,73 @@
+    {% if table.actions|length == 1 %}
+    {% for name, action in table.actions.items() %}
+    actionId = {{action.id}}; // {{name}}
+    //expectedParams = {{ action.attr_params|length }};
+    {% endfor %}
+    {% else %}
+    // Search the action
+    for (uint32_t i = 0; i < attr_count; i++)
+    {
+        if (SAI_{{ api.name | upper }}_ATTR_ACTION == attr_list[i].id)
+        {
+            switch(attr_list[i].value.s32)
+            {
+                {% for name, action in table.actions.items() %}
+                case {{ name }}:
+                {
+                    actionId = {{action.id}};
+                    //expectedParams = {{ action.attr_params|length }};
+                    break;
+                }
+                {% endfor %}
+                default:
+                    DASH_LOG_ERROR("attribute value [%d] %d not supported yet", i, attr_list[i].value.s32);
+                    break;
+            }
+            // only one action
+            break;
+        }
+    }
+    {% endif %}
+    action->set_action_id(actionId);
+
+    for (uint32_t i = 0; i < attr_count; i++)
+    {
+        auto *md = sai_metadata_get_attr_metadata((sai_object_type_t)SAI_OBJECT_TYPE_{{ api.name | upper }}, attr_list[i].id);
+
+        const char* attrName = md ? md->attridname : "unknown";
+
+        switch(attr_list[i].id)
+        {
+        {% set attr_id_list = [] %}
+        {% for name, action in table.actions.items() %}
+            {% for param_name, param in action.attr_params.items() %}
+            {% if param_name in attr_id_list %}{% continue %}{% endif %}
+            {% do attr_id_list.append( param_name ) %}
+            {% if param.skipattr == 'true' %}
+            {% else %}
+            case {{ param_name }}:
+            {
+                auto param = action->add_params();
+                param->set_param_id({{param.id}});
+                {{param.field}}SetVal(attr_list[i].value, param, {{param.bitwidth}});
+                //matchedParams++;
+                {% if param.ip_is_v6_field_id != 0 %}
+                {
+                    // set ip_is_v6_field_id field
+                    auto param2 = action->add_params();
+                    param2->set_param_id({{param.ip_is_v6_field_id}});
+                    booldataSetVal((attr_list[i].value.ipaddr.addr_family == SAI_IP_ADDR_FAMILY_IPV4) ? 0 : 1, param2, 1);
+                    //matchedParams++;
+                }
+                {% endif %}
+                break;
+            }
+            {% endif %}
+            {% endfor %}
+        {% endfor %}
+            default:
+                DASH_LOG_ERROR("attribute [%d] %d %s not supported yet", i, attr_list[i].id, attrName);
+                break;
+        }
+    }
+

dash-pipeline/SAI/templates/impls/p4_table_entry_match.cpp.j2

@@ -0,0 +1,24 @@
+    {% import 'templates/impls/p4_table_util.cpp.j2' as util %}
+    {% for key in table['keys'] %}
+    {% set value = 'tableEntry->' ~ key.name|lower %}
+    {
+        auto mf = matchActionEntry->add_match();
+        mf->set_field_id({{key.id}});
+        {% if key.match_type == 'exact' %}{{ util.set_key_exact(key, value) }}
+        {% elif key.match_type == 'lpm' %}{{ util.set_key_lpm(key, value) }}
+        {% elif key.match_type == 'ternary' %}{{ util.set_key_ternary(key, value) }}
+        {% elif key.match_type == 'optional' %}{{ util.set_key_optional(key, value) }}
+        {% elif key.match_type == 'list' %}{{ util.set_key_list(key, value) }}
+        {% elif key.match_type == 'range_list' %}{{ util.set_key_range_list(key, value) }}
+        {% endif %}
+    }
+    {% if key.ip_is_v6_field_id != 0 %}
+    {
+        // set ip_is_v6_field_id field
+        auto mf = matchActionEntry->add_match();
+        mf->set_field_id({{key.ip_is_v6_field_id}});
+        auto mf_exact = mf->mutable_exact();
+        booldataSetVal(({{value}}.addr_family == SAI_IP_ADDR_FAMILY_IPV4) ? 0 : 1, mf_exact, 1);
+    }
+    {% endif %}
+    {% endfor %}

dash-pipeline/SAI/templates/impls/p4_table_object_match.cpp.j2

@@ -0,0 +1,66 @@
+    {% import 'templates/impls/p4_table_util.cpp.j2' as util %}
+    {% for key in table['keys'] %}
+    {% if key.is_object_key %}
+    auto key_mf = matchActionEntry->add_match();
+    key_mf->set_field_id({{key.id}});
+    auto key_mf_exact = key_mf->mutable_exact();
+    // {{key.field}}SetVal(objId, key_mf_exact, {{key.bitwidth}});
+    {{key.field}}SetVal(static_cast<uint{{ key.bitwidth }}_t>(objId), key_mf_exact, {{ key.bitwidth }});
+    {% endif %}
+    {% endfor %}
+
+    // SAI object table with multiple P4 table keys
+    // Copy P4 table keys from appropriate SAI attributes
+    for (uint32_t i = 0; i < attr_count; i++)
+    {
+        auto *md = sai_metadata_get_attr_metadata((sai_object_type_t)SAI_OBJECT_TYPE_{{ api.name | upper }}, attr_list[i].id);
+
+        const char* attrName = md ? md->attridname : "unknown";
+
+        switch(attr_list[i].id)
+        {
+            {% for key in table['keys'] %}
+            {% if not key.is_object_key %}
+            {% set value = 'attr_list[i].value' %}
+            case SAI_{{ api.name | upper }}_ATTR_{{ key.name | upper }}:
+            {
+                auto mf = matchActionEntry->add_match();
+                mf->set_field_id({{key.id}});
+            {% filter indent(8, True) %}
+                {% if key.match_type == 'exact' %}{{ util.set_key_in_attr_exact(key, value) }}
+                {% elif key.match_type == 'lpm' %}{{ util.set_key_lpm(key, value) }}
+                {% elif key.match_type == 'ternary' %}{{ util.set_key_in_attr_ternary(api, key, value) }}
+                {% elif key.match_type == 'optional' %}{{ util.set_key_optional(key, value) }}
+                {% elif key.match_type == 'list' %}{{ util.set_key_list(key, value) }}
+                {% elif key.match_type == 'range_list' %}{{ util.set_key_range_list(key, value) }}
+                {% endif %}
+            {% endfilter %}
+                {% if key.ip_is_v6_field_id != 0 %}
+                {
+                    // set ip_is_v6_field_id field
+                    auto mf = matchActionEntry->add_match();
+                    mf->set_field_id({{key.ip_is_v6_field_id}});
+                    auto mf_exact = mf->mutable_exact();
+                    booldataSetVal(({{value}}.ipaddr.addr_family == SAI_IP_ADDR_FAMILY_IPV4) ? 0 : 1, mf_exact, 1);
+                }
+                {% endif %}
+                break;
+            }
+            {% endif%}
+            {% endfor %}
+            {% if table['keys'] | selectattr('match_type', 'ne', 'exact') | list | length > 0 %}
+            {% if table['keys'] | selectattr('match_type', 'eq', 'lpm') | list | length == 0 %}
+            // Table has non lpm ternary keys - add priority field
+            case SAI_{{ api.name | upper }}_ATTR_PRIORITY:
+            {
+                matchActionEntry->set_priority(attr_list[i].value.u32);
+                break;
+            }
+            {% endif %}
+            {% endif %}
+            default:
+                DASH_LOG_ERROR("attribute [%d] %d %s not supported yet", i, attr_list[i].id, attrName);
+                break;
+        }
+    }
+

dash-pipeline/SAI/templates/impls/p4_table_util.cpp.j2

@@ -0,0 +1,70 @@
+{% macro set_key_exact(key, value) %}
+        auto mf_exact = mf->mutable_exact();
+    {% if key.field in ['ipaddr','mac'] or key.bitwidth in [24] %}
+        {{key.field}}SetVal({{value}}, mf_exact, {{key.bitwidth}});
+    {%- else %}
+        {{key.field}}SetVal(static_cast<uint{{key.bitwidth}}_t>({{value}}), mf_exact, {{key.bitwidth}});
+    {%- endif %}
+{%- endmacro -%}
+
+{% macro set_key_in_attr_exact(key, value) %}
+        auto mf_exact = mf->mutable_exact();
+        {{key.field}}SetVal({{value}}, mf_exact, {{key.bitwidth}});
+{%- endmacro -%}
+
+{% macro set_key_lpm(key, value) %}
+    {% if key.field == 'ipPrefix' %}
+        if (getPrefixLength({{value}}) == 0)
+        {
+            // https://github.com/p4lang/PI/blob/24e0a3c08c964e36d235973556b90e0ae922b894/proto/frontend/src/device_mgr.cpp#L2242-L2246
+            DASH_LOG_WARN("Invalid reprsentation of 'don't care' LPM match, omit match field instead of using a prefix length of 0");
+            return SAI_STATUS_SUCCESS;
+        }
+    {% endif %}
+        auto mf_lpm = mf->mutable_lpm();
+        {{key.field}}SetVal({{value}}, mf_lpm, {{key.bitwidth}});
+{%- endmacro -%}
+
+{% macro set_key_in_attr_ternary(api, key, value) %}
+        auto mf_ternary = mf->mutable_ternary();
+        {{key.field}}SetVal({{value}}, mf_ternary, {{key.bitwidth}});
+        auto mask = getMaskAttr(SAI_{{ api.name | upper }}_ATTR_{{ key.name | upper }}_MASK, attr_count, attr_list);
+        assert(mask && "SAI_{{ api.name | upper }}_ATTR_{{ key.name | upper }}_MASK isn't provided");
+        {{key.field}}SetMask(mask->value, mf_ternary, {{key.bitwidth}});
+{%- endmacro -%}
+
+{% macro set_key_ternary(key, value) %}
+        auto mf_ternary = mf->mutable_ternary();
+        {{key.field}}SetVal({{value}}, mf_ternary, {{key.bitwidth}});
+        {{key.field}}SetMask({{value}}_mask, mf_ternary, {{key.bitwidth}});
+        matchActionEntry->set_priority(tableEntry->priority);
+{%- endmacro -%}
+
+{% macro set_key_optional(key, value) %}
+        auto mf_optional = mf->mutable_optional();
+        {{key.field}}SetVal({{value}}, mf_optional, {{key.bitwidth}});
+{%- endmacro -%}
+
+{% macro set_key_list(key, value) %}
+        // BMv2 doesn't support "list" match type, and we are using "optional" match in v1model as our implementation.
+        // Hence, here we only take the first item from the list and program it as optional match.
+        assert({{value}}.{{key.field}}.count == 1 && "BMv2 only supports one item in list match type");
+        auto mf_optional = mf->mutable_optional();
+        sai_attribute_value_t attr_val;
+    {% if key.field == 'ipprefixlist' %}
+        attr_val.ipaddr.addr_family = {{value}}.ipprefixlist.list[0].addr_family;
+        attr_val.ipaddr.addr = {{value}}.ipprefixlist.list[0].addr;
+        ipaddrSetVal(attr_val, mf_optional, {{key.bitwidth}});
+    {%- else %}
+        attr_val.{{ key.field | replace('list', '') }} = {{value}}.{{key.field}}.list[0];
+        {{ key.field | replace('list', '') }}SetVal(attr_val, mf_optional, {{key.bitwidth}});
+    {%- endif %}
+{%- endmacro -%}
+
+{% macro set_key_range_list(key, value) %}
+        // BMv2 doesn't support "range_list" match type, and we are using "optional" match in v1model as our implementation.
+        // Hence, here we only take the first item from the list and program the range start as optional match.
+        assert(attr_list[i].value.{{key.field}}.count == 1 && "BMv2 only supports one item in list match type");
+        auto mf_optional = mf->mutable_optional();
+        {{ key.field | replace('rangelist', '') }}SetVal(attr_list[i].value.{{key.field}}.list[0].min, mf_optional, {{key.bitwidth}});
+{%- endmacro -%}

dash-pipeline/SAI/templates/impls/sai_api_func_bulk.cpp.j2

@@ -0,0 +1,110 @@
+{% if api.is_object == True %}
+static sai_status_t dash_sai_create_{{ api.name }}s(
+        _In_ sai_object_id_t switch_id,
+        _In_ uint32_t object_count,
+        _In_ const uint32_t *attr_count,
+        _In_ const sai_attribute_t **attr_list,
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_object_id_t *object_id,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+    return dash::DashSai::bulk_create_objects(dash_sai_create_{{ api.name }}, switch_id, object_count, attr_count, attr_list, mode, object_id, object_statuses);
+}
+
+static sai_status_t dash_sai_remove_{{ api.name }}s(
+        _In_ uint32_t object_count,
+        _In_ const sai_object_id_t *object_id,
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+    return dash::DashSai::bulk_remove_objects(dash_sai_remove_{{ api.name }}, object_count, object_id, mode, object_statuses);
+}
+{% else %}
+static sai_status_t dash_sai_create_{{ api.name | replace("entry", "entries") }}(
+        _In_ uint32_t object_count,
+        _In_ const sai_{{ api.name }}_t *{{ api.name }},
+        _In_ const uint32_t *attr_count,
+        _In_ const sai_attribute_t **attr_list,
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+
+    sai_status_t agg_status = SAI_STATUS_SUCCESS;
+
+    for (uint32_t i = 0; i < object_count; i++)
+    {
+        object_statuses[i] = dash_sai_create_{{ api.name }}(&{{ api.name }}[i], attr_count[i], attr_list[i]);
+
+        if (object_statuses[i] != SAI_STATUS_SUCCESS)
+        {
+            agg_status = SAI_STATUS_FAILURE;
+        }
+
+        if (agg_status == SAI_STATUS_FAILURE && mode == SAI_BULK_OP_ERROR_MODE_STOP_ON_ERROR)
+        {
+            return agg_status;
+        }
+    }
+
+    return agg_status;
+}
+
+static sai_status_t dash_sai_remove_{{ api.name | replace("entry", "entries") }}(
+        _In_ uint32_t object_count,
+        _In_ const sai_{{ api.name }}_t *{{ api.name }},
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+
+    sai_status_t agg_status = SAI_STATUS_SUCCESS;
+
+    for (uint32_t i = 0; i < object_count; i++)
+    {
+        object_statuses[i] = dash_sai_remove_{{ api.name }}(&{{ api.name }}[i]);
+
+        if (object_statuses[i] != SAI_STATUS_SUCCESS)
+        {
+            agg_status = SAI_STATUS_FAILURE;
+        }
+
+        if (agg_status == SAI_STATUS_FAILURE && mode == SAI_BULK_OP_ERROR_MODE_STOP_ON_ERROR)
+        {
+            return agg_status;
+        }
+    }
+
+    return agg_status;
+}
+{% if api.name == 'route_entry' %}
+
+static sai_status_t dash_sai_set_{{ api.name | replace("entry", "entries") }}_attribute(
+        _In_ uint32_t object_count,
+        _In_ const sai_route_entry_t *route_entry,
+        _In_ const sai_attribute_t *attr_list,
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+    assert(0 && "sai_set_{{ api.name | replace("entry", "entries") }}_attribute NYI");
+    return SAI_STATUS_FAILURE;
+}
+
+static sai_status_t dash_sai_get_{{ api.name | replace("entry", "entries") }}_attribute(
+        _In_ uint32_t object_count,
+        _In_ const sai_route_entry_t *route_entry,
+        _In_ const uint32_t *attr_count,
+        _Inout_ sai_attribute_t **attr_list,
+        _In_ sai_bulk_op_error_mode_t mode,
+        _Out_ sai_status_t *object_statuses)
+{
+    DASH_LOG_ENTER();
+    assert(0 && "sai_get_{{ api.name | replace("entry", "entries") }}_attribute NYI");
+    return SAI_STATUS_FAILURE;
+}
+{% endif %}
+{% endif %}
+