https://jira.opendaylight.org This file is an XML representation of an issue en-us 8.20.10 820010 22-06-2022 https://jira.opendaylight.org/browse/YANGTOOLS-1076 yangtools <p>Current layout of SchemaPath favors instantiation of temporary paths and their retention in the object, which means we will end up eating up memory even after we have completed all that is needed. Furthermore we are caching hashCode in the SchemaPath object.</p> <p>This results in the following layout:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>***** 32-bit VM: ********************************************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 8 (object header) N/A 8 4 int SchemaPath.hash N/A 12 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 16 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 20 4 com.google.common.collect.ImmutableList SchemaPath.legacyPath N/A Instance size: 24 bytes Space losses: 0 bytes internal + 0 bytes external = 0 bytes total ***** 64-bit VM: ********************************************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 16 (object header) N/A 16 4 int SchemaPath.hash N/A 20 4 (alignment/padding gap) 24 8 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 32 8 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 40 8 com.google.common.collect.ImmutableList SchemaPath.legacyPath N/A Instance size: 48 bytes Space losses: 4 bytes internal + 0 bytes external = 4 bytes total ***** 64-bit VM, compressed references enabled: *************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 12 (object header) N/A 12 4 int SchemaPath.hash N/A 16 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 20 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 24 4 com.google.common.collect.ImmutableList SchemaPath.legacyPath N/A 28 4 (loss due to the next object alignment) Instance size: 32 bytes Space losses: 0 bytes internal + 4 bytes external = 4 bytes total ***** 64-bit VM, compressed references enabled, 16-byte align: ************ org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 12 (object header) N/A 12 4 int SchemaPath.hash N/A 16 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 20 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 24 4 com.google.common.collect.ImmutableList SchemaPath.legacyPath N/A 28 4 (loss due to the next object alignment) Instance size: 32 bytes Space losses: 0 bytes internal + 4 bytes external = 4 bytes total </pre> </div></div> <p>Losing either hash code or the legacy path would improve the situation by 16-25%, making SchemaContext a tad smaller.</p> YANGTOOLS-1076

Trim down SchemaPath size

Story Medium Resolved Done Robert Varga Robert Varga Wed, 22 Jan 2020 14:08:12 +0000 Wed, 12 Feb 2020 12:02:01 +0000 Wed, 12 Feb 2020 11:59:53 +0000 5.0.0 parser 0 1 <p>SchemaNodes relying on hashCode()/equals() could ruin our efficiency here.</p> <p>For legacyPath we can most probably create some sort of backwards/forwards collection, similar to what we are doing for PathArguments in YangInstanceIdentifier. The hashCode cache can probably go, as we do not really expect it to be looked up anymore – aside from UsesNode, which will need to be taught some other trick to track its refines.</p> <p>The resulting layout looks like this:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>***** 32-bit VM: ********************************************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 8 (object header) N/A 8 4 int SchemaPath.hash N/A 12 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 16 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 20 4 (loss due to the next object alignment) Instance size: 24 bytes Space losses: 0 bytes internal + 4 bytes external = 4 bytes total ***** 64-bit VM: ********************************************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 16 (object header) N/A 16 4 int SchemaPath.hash N/A 20 4 (alignment/padding gap) 24 8 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 32 8 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A Instance size: 40 bytes Space losses: 4 bytes internal + 0 bytes external = 4 bytes total ***** 64-bit VM, compressed references enabled: *************************** org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 12 (object header) N/A 12 4 int SchemaPath.hash N/A 16 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 20 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A Instance size: 24 bytes Space losses: 0 bytes internal + 0 bytes external = 0 bytes total ***** 64-bit VM, compressed references enabled, 16-byte align: ************ org.opendaylight.yangtools.yang.model.api.SchemaPath object internals: OFFSET SIZE TYPE DESCRIPTION VALUE 0 12 (object header) N/A 12 4 int SchemaPath.hash N/A 16 4 org.opendaylight.yangtools.yang.model.api.SchemaPath SchemaPath.parent N/A 20 4 org.opendaylight.yangtools.yang.common.QName SchemaPath.qname N/A 24 8 (loss due to the next object alignment) Instance size: 32 bytes Space losses: 0 bytes internal + 8 bytes external = 8 bytes total </pre> </div></div> <p> </p> Blocks YANGTOOLS-761 Development Epic Link YANGTOOLS-1066 Rank 0|i03qwv: