Factor out PosOccFieldParams and PosOccFieldsParams from posocccompression

compilation unit.

15 files changed, 432 insertions, 358 deletions

diff --git a/searchlib/src/vespa/searchlib/bitcompression/CMakeLists.txt b/searchlib/src/vespa/searchlib/bitcompression/CMakeLists.txt
index 9573573652b..bebfccc6433 100644
--- a/searchlib/src/vespa/searchlib/bitcompression/CMakeLists.txt
+++ b/searchlib/src/vespa/searchlib/bitcompression/CMakeLists.txt
@@ -5,5 +5,7 @@ vespa_add_library(searchlib_bitcompression OBJECT
     countcompression.cpp
     pagedict4.cpp
     posocccompression.cpp
+    posocc_fields_params.cpp
+    posocc_field_params.cpp
     DEPENDS
 )
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.cpp b/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.cpp
new file mode 100644
index 00000000000..006c0b29ffb
--- /dev/null
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.cpp
@@ -0,0 +1,190 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include "posocc_field_params.h"
+#include <vespa/searchcommon/common/schema.h>
+#include <vespa/searchlib/index/postinglistparams.h>
+#include <vespa/vespalib/data/fileheader.h>
+#include <vespa/vespalib/stllike/asciistream.h>
+
+#include <vespa/log/log.h>
+LOG_SETUP(".posocc_field_params");
+
+using vespalib::GenericHeader;
+
+namespace search::bitcompression {
+
+namespace schema = search::index::schema;
+
+PosOccFieldParams::PosOccFieldParams()
+    : _elemLenK(0),
+      _hasElements(false),
+      _hasElementWeights(false),
+      _avgElemLen(512),
+      _collectionType(SINGLE),
+      _name()
+{ }
+
+
+bool
+PosOccFieldParams::operator==(const PosOccFieldParams &rhs) const
+{
+    return _collectionType == rhs._collectionType &&
+              _avgElemLen == rhs._avgElemLen &&
+                     _name == rhs._name;
+}
+
+
+vespalib::string
+PosOccFieldParams::getParamsPrefix(uint32_t idx)
+{
+    vespalib::asciistream paramsPrefix;
+    paramsPrefix << "fieldParams.";
+    paramsPrefix << idx;
+    return paramsPrefix.str();
+}
+
+
+void
+PosOccFieldParams::getParams(PostingListParams &params, uint32_t idx) const
+{
+    vespalib::string paramsPrefix = getParamsPrefix(idx);
+    vespalib::string collStr = paramsPrefix + ".collectionType";
+    vespalib::string avgElemLenStr = paramsPrefix + ".avgElemLen";
+    vespalib::string nameStr = paramsPrefix + ".name";
+
+    switch (_collectionType) {
+    case SINGLE:
+        params.setStr(collStr, "single");
+        break;
+    case ARRAY:
+        params.setStr(collStr, "array");
+        break;
+    case WEIGHTEDSET:
+        params.setStr(collStr, "weightedSet");
+        break;
+    }
+    params.set(avgElemLenStr, _avgElemLen);
+    params.setStr(nameStr, _name);
+}
+
+
+void
+PosOccFieldParams::setParams(const PostingListParams &params, uint32_t idx)
+{
+    vespalib::string paramsPrefix = getParamsPrefix(idx);
+    vespalib::string collStr = paramsPrefix + ".collectionType";
+    vespalib::string avgElemLenStr = paramsPrefix + ".avgElemLen";
+    vespalib::string nameStr = paramsPrefix + ".name";
+
+    if (params.isSet(collStr)) {
+        vespalib::string collVal = params.getStr(collStr);
+        if (collVal == "single") {
+            _collectionType = SINGLE;
+            _hasElements = false;
+            _hasElementWeights = false;
+        } else if (collVal == "array") {
+            _collectionType = ARRAY;
+            _hasElements = true;
+            _hasElementWeights = false;
+        } else if (collVal == "weightedSet") {
+            _collectionType = WEIGHTEDSET;
+            _hasElements = true;
+            _hasElementWeights = true;
+        }
+    }
+    params.get(avgElemLenStr, _avgElemLen);
+    if (params.isSet(nameStr)) {
+        _name = params.getStr(nameStr);
+    }
+}
+
+
+void
+PosOccFieldParams::setSchemaParams(const Schema &schema, uint32_t fieldId)
+{
+    assert(fieldId < schema.getNumIndexFields());
+    const Schema::IndexField &field = schema.getIndexField(fieldId);
+    switch (field.getCollectionType()) {
+    case schema::CollectionType::SINGLE:
+        _collectionType = SINGLE;
+        _hasElements = false;
+        _hasElementWeights = false;
+        break;
+    case schema::CollectionType::ARRAY:
+        _collectionType = ARRAY;
+        _hasElements = true;
+        _hasElementWeights = false;
+        break;
+    case schema::CollectionType::WEIGHTEDSET:
+        _collectionType = WEIGHTEDSET;
+        _hasElements = true;
+        _hasElementWeights = true;
+        break;
+    default:
+        LOG(error, "Bad collection type");
+        LOG_ABORT("should not be reached");
+    }
+    _avgElemLen = field.getAvgElemLen();
+    _name = field.getName();
+}
+
+
+void
+PosOccFieldParams::readHeader(const vespalib::GenericHeader &header,
+                              const vespalib::string &prefix)
+{
+    vespalib::string nameKey(prefix + "fieldName");
+    vespalib::string collKey(prefix + "collectionType");
+    vespalib::string avgElemLenKey(prefix + "avgElemLen");
+    _name = header.getTag(nameKey).asString();
+    Schema::CollectionType ct = schema::collectionTypeFromName(header.getTag(collKey).asString());
+    switch (ct) {
+    case schema::CollectionType::SINGLE:
+        _collectionType = SINGLE;
+        _hasElements = false;
+        _hasElementWeights = false;
+        break;
+    case schema::CollectionType::ARRAY:
+        _collectionType = ARRAY;
+        _hasElements = true;
+        _hasElementWeights = false;
+        break;
+    case schema::CollectionType::WEIGHTEDSET:
+        _collectionType = WEIGHTEDSET;
+        _hasElements = true;
+        _hasElementWeights = true;
+        break;
+    default:
+        LOG_ABORT("Bad collection type when reading field param in header");
+    }
+    _avgElemLen = header.getTag(avgElemLenKey).asInteger();
+}
+
+
+void
+PosOccFieldParams::writeHeader(vespalib::GenericHeader &header,
+                               const vespalib::string &prefix) const
+{
+    vespalib::string nameKey(prefix + "fieldName");
+    vespalib::string collKey(prefix + "collectionType");
+    vespalib::string avgElemLenKey(prefix + "avgElemLen");
+    header.putTag(GenericHeader::Tag(nameKey, _name));
+    Schema::CollectionType ct(schema::CollectionType::SINGLE);
+    switch (_collectionType) {
+    case SINGLE:
+        ct = schema::CollectionType::SINGLE;
+        break;
+    case ARRAY:
+        ct = schema::CollectionType::ARRAY;
+        break;
+    case WEIGHTEDSET:
+        ct = schema::CollectionType::WEIGHTEDSET;
+        break;
+    default:
+        LOG_ABORT("Bad collection type when writing field param in header");
+    }
+    header.putTag(GenericHeader::Tag(collKey, schema::getTypeName(ct)));
+    header.putTag(GenericHeader::Tag(avgElemLenKey, _avgElemLen));
+}
+
+}
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.h b/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.h
new file mode 100644
index 00000000000..c781cec4db5
--- /dev/null
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocc_field_params.h
@@ -0,0 +1,49 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include <cstdint>
+#include <vespa/vespalib/stllike/string.h>
+
+namespace search::index {
+class PostingListParams;
+class Schema;
+}
+
+namespace vespalib { class GenericHeader; }
+
+namespace search::bitcompression {
+
+class PosOccFieldParams
+{
+public:
+    typedef index::PostingListParams PostingListParams;
+    typedef index::Schema Schema;
+
+    enum CollectionType
+    {
+        SINGLE,
+        ARRAY,
+        WEIGHTEDSET
+    };
+
+    uint8_t _elemLenK;
+    bool    _hasElements;
+    bool    _hasElementWeights;
+    uint32_t _avgElemLen;
+    CollectionType _collectionType;
+    vespalib::string _name;
+
+    PosOccFieldParams();
+
+    bool operator==(const PosOccFieldParams &rhs) const;
+    static vespalib::string getParamsPrefix(uint32_t idx);
+    void getParams(PostingListParams &params, uint32_t idx) const;
+    void setParams(const PostingListParams &params, uint32_t idx);
+    void setSchemaParams(const Schema &schema, uint32_t fieldId);
+    void readHeader(const vespalib::GenericHeader &header, const vespalib::string &prefix);
+    void writeHeader(vespalib::GenericHeader &header, const vespalib::string &prefix) const;
+};
+
+}
+
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.cpp b/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.cpp
new file mode 100644
index 00000000000..2e2674f98c6
--- /dev/null
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.cpp
@@ -0,0 +1,132 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include "posocc_fields_params.h"
+#include <vespa/searchlib/index/postinglistparams.h>
+#include <vespa/searchlib/index/schemautil.h>
+#include <vespa/vespalib/data/fileheader.h>
+#include <vespa/vespalib/stllike/asciistream.h>
+
+#include <vespa/log/log.h>
+LOG_SETUP(".posocc_fields_params");
+
+using search::index::SchemaUtil;
+using vespalib::GenericHeader;
+
+namespace search::bitcompression {
+
+PosOccFieldsParams::PosOccFieldsParams()
+    : _numFields(0u),
+      _fieldParams(nullptr),
+      _params()
+{
+}
+
+PosOccFieldsParams::PosOccFieldsParams(const PosOccFieldsParams &rhs)
+    : _numFields(0u),
+      _fieldParams(nullptr),
+      _params(rhs._params)
+{
+    cacheParamsRef();
+}
+
+PosOccFieldsParams &
+PosOccFieldsParams::operator=(const PosOccFieldsParams &rhs)
+{
+    assertCachedParamsRef();
+    _params = rhs._params;
+    cacheParamsRef();
+    return *this;
+}
+
+
+bool
+PosOccFieldsParams::operator==(const PosOccFieldsParams &rhs) const
+{
+    return _params == rhs._params;
+}
+
+
+void
+PosOccFieldsParams::getParams(PostingListParams &params) const
+{
+    assertCachedParamsRef();
+    assert(_numFields == 1u); // Only single field for now
+    params.set("numFields", _numFields);
+    // Single posting file index format will have multiple fields in file
+    for (uint32_t field = 0; field < _numFields; ++field) {
+        _fieldParams[field].getParams(params, field);
+    }
+}
+
+
+void
+PosOccFieldsParams::setParams(const PostingListParams &params)
+{
+    assertCachedParamsRef();
+    uint32_t numFields = _numFields;
+    params.get("numFields", numFields);
+    assert(numFields == 1u);
+    _params.resize(numFields);
+    cacheParamsRef();
+    // Single posting file index format will have multiple fields in file
+    for (uint32_t field = 0; field < numFields; ++field) {
+        _params[field].setParams(params, field);
+    }
+}
+
+
+void
+PosOccFieldsParams::setSchemaParams(const Schema &schema,
+                                    const uint32_t indexId)
+{
+    assertCachedParamsRef();
+    SchemaUtil::IndexIterator i(schema, indexId);
+    assert(i.isValid());
+    _params.resize(1u);
+    cacheParamsRef();
+    const Schema::IndexField &field = schema.getIndexField(indexId);
+    if (!SchemaUtil::validateIndexField(field)) {
+        LOG_ABORT("should not be reached");
+    }
+    _params[0].setSchemaParams(schema, indexId);
+}
+
+
+void
+PosOccFieldsParams::readHeader(const vespalib::GenericHeader &header,
+               const vespalib::string &prefix)
+{
+    vespalib::string numFieldsKey(prefix + "numFields");
+    assertCachedParamsRef();
+    uint32_t numFields = header.getTag(numFieldsKey).asInteger();
+    assert(numFields == 1u);
+    _params.resize(numFields);
+    cacheParamsRef();
+    // Single posting file index format will have multiple fields in file
+    for (uint32_t field = 0; field < numFields; ++field) {
+        vespalib::asciistream as;
+        as << prefix << "field[" << field << "].";
+        vespalib::string subPrefix(as.str());
+        _params[field].readHeader(header, subPrefix);
+    }
+}
+
+
+void
+PosOccFieldsParams::writeHeader(vespalib::GenericHeader &header,
+                                const vespalib::string &prefix) const
+{
+    vespalib::string numFieldsKey(prefix + "numFields");
+    assertCachedParamsRef();
+    assert(_numFields == 1u);
+    header.putTag(GenericHeader::Tag(numFieldsKey, _numFields));
+    // Single posting file index format will have multiple fields in file
+    for (uint32_t field = 0; field < _numFields; ++field) {
+        vespalib::asciistream as;
+        as << prefix << "field[" << field << "].";
+        vespalib::string subPrefix(as.str());
+        _params[field].writeHeader(header, subPrefix);
+    }
+}
+
+}
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.h b/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.h
new file mode 100644
index 00000000000..f6ae886b3f0
--- /dev/null
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocc_fields_params.h
@@ -0,0 +1,49 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include "posocc_field_params.h"
+#include <vector>
+#include <cassert>
+
+namespace search::bitcompression {
+
+class PosOccFieldsParams
+{
+    // Cache pointers.
+    uint32_t _numFields;
+    const PosOccFieldParams *_fieldParams;
+
+    // Storage
+    std::vector<PosOccFieldParams> _params;
+
+public:
+    typedef index::PostingListParams PostingListParams;
+    typedef index::Schema Schema;
+
+    PosOccFieldsParams();
+    PosOccFieldsParams(const PosOccFieldsParams &rhs);
+
+    PosOccFieldsParams &operator=(const PosOccFieldsParams &rhs);
+    bool operator==(const PosOccFieldsParams &rhs) const;
+
+    void cacheParamsRef() {
+        _numFields = _params.size();
+        _fieldParams = _params.empty() ? nullptr : &_params[0];
+    }
+
+    void assertCachedParamsRef() const {
+        assert(_numFields == _params.size());
+        assert(_fieldParams == (_params.empty() ? nullptr : &_params[0]));
+    }
+
+    uint32_t getNumFields() const { return _numFields; }
+    const PosOccFieldParams *getFieldParams() const { return _fieldParams; }
+    void getParams(PostingListParams &params) const;
+    void setParams(const PostingListParams &params);
+    void setSchemaParams(const Schema &schema, const uint32_t indexId);
+    void readHeader(const vespalib::GenericHeader &header, const vespalib::string &prefix);
+    void writeHeader(vespalib::GenericHeader &header, const vespalib::string &prefix) const;
+};
+
+}
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocccompression.cpp b/searchlib/src/vespa/searchlib/bitcompression/posocccompression.cpp
index 9f5d3cf751f..30c3ac4a7d2 100644
--- a/searchlib/src/vespa/searchlib/bitcompression/posocccompression.cpp
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocccompression.cpp
@@ -2,6 +2,7 @@
 
 #include "compression.h"
 #include "posocccompression.h"
+#include "posocc_fields_params.h"
 #include <vespa/searchlib/index/schemautil.h>
 #include <vespa/searchlib/fef/termfieldmatchdata.h>
 #include <vespa/searchlib/fef/termfieldmatchdataarray.h>
@@ -31,295 +32,6 @@ vespalib::string EG64PosOccId2 = "EG64PosOcc.2";    // Fixed k values
 namespace search::bitcompression {
 
 
-PosOccFieldParams::PosOccFieldParams()
-    : _elemLenK(0),
-      _hasElements(false),
-      _hasElementWeights(false),
-      _avgElemLen(512),
-      _collectionType(SINGLE),
-      _name()
-{ }
-
-
-bool
-PosOccFieldParams::operator==(const PosOccFieldParams &rhs) const
-{
-    return _collectionType == rhs._collectionType &&
-              _avgElemLen == rhs._avgElemLen &&
-                     _name == rhs._name;
-}
-
-
-vespalib::string
-PosOccFieldParams::getParamsPrefix(uint32_t idx)
-{
-    vespalib::asciistream paramsPrefix;
-    paramsPrefix << "fieldParams.";
-    paramsPrefix << idx;
-    return paramsPrefix.str();
-}
-
-
-void
-PosOccFieldParams::getParams(PostingListParams &params, uint32_t idx) const
-{
-    vespalib::string paramsPrefix = getParamsPrefix(idx);
-    vespalib::string collStr = paramsPrefix + ".collectionType";
-    vespalib::string avgElemLenStr = paramsPrefix + ".avgElemLen";
-    vespalib::string nameStr = paramsPrefix + ".name";
-
-    switch (_collectionType) {
-    case SINGLE:
-        params.setStr(collStr, "single");
-        break;
-    case ARRAY:
-        params.setStr(collStr, "array");
-        break;
-    case WEIGHTEDSET:
-        params.setStr(collStr, "weightedSet");
-        break;
-    }
-    params.set(avgElemLenStr, _avgElemLen);
-    params.setStr(nameStr, _name);
-}
-
-
-void
-PosOccFieldParams::setParams(const PostingListParams &params, uint32_t idx)
-{
-    vespalib::string paramsPrefix = getParamsPrefix(idx);
-    vespalib::string collStr = paramsPrefix + ".collectionType";
-    vespalib::string avgElemLenStr = paramsPrefix + ".avgElemLen";
-    vespalib::string nameStr = paramsPrefix + ".name";
-
-    if (params.isSet(collStr)) {
-        vespalib::string collVal = params.getStr(collStr);
-        if (collVal == "single") {
-            _collectionType = SINGLE;
-            _hasElements = false;
-            _hasElementWeights = false;
-        } else if (collVal == "array") {
-            _collectionType = ARRAY;
-            _hasElements = true;
-            _hasElementWeights = false;
-        } else if (collVal == "weightedSet") {
-            _collectionType = WEIGHTEDSET;
-            _hasElements = true;
-            _hasElementWeights = true;
-        }
-    }
-    params.get(avgElemLenStr, _avgElemLen);
-    if (params.isSet(nameStr)) {
-        _name = params.getStr(nameStr);
-    }
-}
-
-
-void
-PosOccFieldParams::setSchemaParams(const Schema &schema, uint32_t fieldId)
-{
-    assert(fieldId < schema.getNumIndexFields());
-    const Schema::IndexField &field = schema.getIndexField(fieldId);
-    switch (field.getCollectionType()) {
-    case schema::CollectionType::SINGLE:
-        _collectionType = SINGLE;
-        _hasElements = false;
-        _hasElementWeights = false;
-        break;
-    case schema::CollectionType::ARRAY:
-        _collectionType = ARRAY;
-        _hasElements = true;
-        _hasElementWeights = false;
-        break;
-    case schema::CollectionType::WEIGHTEDSET:
-        _collectionType = WEIGHTEDSET;
-        _hasElements = true;
-        _hasElementWeights = true;
-        break;
-    default:
-        LOG(error, "Bad collection type");
-        LOG_ABORT("should not be reached");
-    }
-    _avgElemLen = field.getAvgElemLen();
-    _name = field.getName();
-}
-
-
-void
-PosOccFieldParams::readHeader(const vespalib::GenericHeader &header,
-                              const vespalib::string &prefix)
-{
-    vespalib::string nameKey(prefix + "fieldName");
-    vespalib::string collKey(prefix + "collectionType");
-    vespalib::string avgElemLenKey(prefix + "avgElemLen");
-    _name = header.getTag(nameKey).asString();
-    Schema::CollectionType ct = schema::collectionTypeFromName(header.getTag(collKey).asString());
-    switch (ct) {
-    case schema::CollectionType::SINGLE:
-        _collectionType = SINGLE;
-        _hasElements = false;
-        _hasElementWeights = false;
-        break;
-    case schema::CollectionType::ARRAY:
-        _collectionType = ARRAY;
-        _hasElements = true;
-        _hasElementWeights = false;
-        break;
-    case schema::CollectionType::WEIGHTEDSET:
-        _collectionType = WEIGHTEDSET;
-        _hasElements = true;
-        _hasElementWeights = true;
-        break;
-    default:
-        LOG_ABORT("Bad collection type when reading field param in header");
-    }
-    _avgElemLen = header.getTag(avgElemLenKey).asInteger();
-}
-
-
-void
-PosOccFieldParams::writeHeader(vespalib::GenericHeader &header,
-                               const vespalib::string &prefix) const
-{
-    vespalib::string nameKey(prefix + "fieldName");
-    vespalib::string collKey(prefix + "collectionType");
-    vespalib::string avgElemLenKey(prefix + "avgElemLen");
-    header.putTag(GenericHeader::Tag(nameKey, _name));
-    Schema::CollectionType ct(schema::CollectionType::SINGLE);
-    switch (_collectionType) {
-    case SINGLE:
-        ct = schema::CollectionType::SINGLE;
-        break;
-    case ARRAY:
-        ct = schema::CollectionType::ARRAY;
-        break;
-    case WEIGHTEDSET:
-        ct = schema::CollectionType::WEIGHTEDSET;
-        break;
-    default:
-        LOG_ABORT("Bad collection type when writing field param in header");
-    }
-    header.putTag(GenericHeader::Tag(collKey, schema::getTypeName(ct)));
-    header.putTag(GenericHeader::Tag(avgElemLenKey, _avgElemLen));
-}
-
-
-PosOccFieldsParams::PosOccFieldsParams()
-    : _numFields(0u),
-      _fieldParams(nullptr),
-      _params()
-{
-}
-
-PosOccFieldsParams::PosOccFieldsParams(const PosOccFieldsParams &rhs)
-    : _numFields(0u),
-      _fieldParams(nullptr),
-      _params(rhs._params)
-{
-    cacheParamsRef();
-}
-
-PosOccFieldsParams &
-PosOccFieldsParams::operator=(const PosOccFieldsParams &rhs)
-{
-    assertCachedParamsRef();
-    _params = rhs._params;
-    cacheParamsRef();
-    return *this;
-}
-
-
-bool
-PosOccFieldsParams::operator==(const PosOccFieldsParams &rhs) const
-{
-    return _params == rhs._params;
-}
-
-
-void
-PosOccFieldsParams::getParams(PostingListParams &params) const
-{
-    assertCachedParamsRef();
-    assert(_numFields == 1u); // Only single field for now
-    params.set("numFields", _numFields);
-    // Single posting file index format will have multiple fields in file
-    for (uint32_t field = 0; field < _numFields; ++field) {
-        _fieldParams[field].getParams(params, field);
-    }
-}
-
-
-void
-PosOccFieldsParams::setParams(const PostingListParams &params)
-{
-    assertCachedParamsRef();
-    uint32_t numFields = _numFields;
-    params.get("numFields", numFields);
-    assert(numFields == 1u);
-    _params.resize(numFields);
-    cacheParamsRef();
-    // Single posting file index format will have multiple fields in file
-    for (uint32_t field = 0; field < numFields; ++field) {
-        _params[field].setParams(params, field);
-    }
-}
-
-
-void
-PosOccFieldsParams::setSchemaParams(const Schema &schema,
-                                    const uint32_t indexId)
-{
-    assertCachedParamsRef();
-    SchemaUtil::IndexIterator i(schema, indexId);
-    assert(i.isValid());
-    _params.resize(1u);
-    cacheParamsRef();
-    const Schema::IndexField &field = schema.getIndexField(indexId);
-    if (!SchemaUtil::validateIndexField(field)) {
-        LOG_ABORT("should not be reached");
-    }
-    _params[0].setSchemaParams(schema, indexId);
-}
-
-
-void
-PosOccFieldsParams::readHeader(const vespalib::GenericHeader &header,
-               const vespalib::string &prefix)
-{
-    vespalib::string numFieldsKey(prefix + "numFields");
-    assertCachedParamsRef();
-    uint32_t numFields = header.getTag(numFieldsKey).asInteger();
-    assert(numFields == 1u);
-    _params.resize(numFields);
-    cacheParamsRef();
-    // Single posting file index format will have multiple fields in file
-    for (uint32_t field = 0; field < numFields; ++field) {
-        vespalib::asciistream as;
-        as << prefix << "field[" << field << "].";
-        vespalib::string subPrefix(as.str());
-        _params[field].readHeader(header, subPrefix);
-    }
-}
-
-
-void
-PosOccFieldsParams::writeHeader(vespalib::GenericHeader &header,
-                                const vespalib::string &prefix) const
-{
-    vespalib::string numFieldsKey(prefix + "numFields");
-    assertCachedParamsRef();
-    assert(_numFields == 1u);
-    header.putTag(GenericHeader::Tag(numFieldsKey, _numFields));
-    // Single posting file index format will have multiple fields in file
-    for (uint32_t field = 0; field < _numFields; ++field) {
-        vespalib::asciistream as;
-        as << prefix << "field[" << field << "].";
-        vespalib::string subPrefix(as.str());
-        _params[field].writeHeader(header, subPrefix);
-    }
-}
-
-
 template <bool bigEndian>
 void
 EG2PosOccDecodeContext<bigEndian>::
diff --git a/searchlib/src/vespa/searchlib/bitcompression/posocccompression.h b/searchlib/src/vespa/searchlib/bitcompression/posocccompression.h
index d500dacd7d4..46f5e2864c0 100644
--- a/searchlib/src/vespa/searchlib/bitcompression/posocccompression.h
+++ b/searchlib/src/vespa/searchlib/bitcompression/posocccompression.h
@@ -58,75 +58,7 @@ public:
 
 namespace search::bitcompression {
 
-class PosOccFieldParams
-{
-public:
-    typedef index::PostingListParams PostingListParams;
-    typedef index::Schema Schema;
-
-    enum CollectionType
-    {
-        SINGLE,
-        ARRAY,
-        WEIGHTEDSET
-    };
-
-    uint8_t _elemLenK;
-    bool    _hasElements;
-    bool    _hasElementWeights;
-    uint32_t _avgElemLen;
-    CollectionType _collectionType;
-    vespalib::string _name;
-
-    PosOccFieldParams();
-
-    bool operator==(const PosOccFieldParams &rhs) const;
-    static vespalib::string getParamsPrefix(uint32_t idx);
-    void getParams(PostingListParams &params, uint32_t idx) const;
-    void setParams(const PostingListParams &params, uint32_t idx);
-    void setSchemaParams(const Schema &schema, uint32_t fieldId);
-    void readHeader(const vespalib::GenericHeader &header, const vespalib::string &prefix);
-    void writeHeader(vespalib::GenericHeader &header, const vespalib::string &prefix) const;
-};
-
-
-class PosOccFieldsParams
-{
-    // Cache pointers.
-    uint32_t _numFields;
-    const PosOccFieldParams *_fieldParams;
-
-    // Storage
-    std::vector<PosOccFieldParams> _params;
-
-public:
-    typedef index::PostingListParams PostingListParams;
-    typedef index::Schema Schema;
-
-    PosOccFieldsParams();
-    PosOccFieldsParams(const PosOccFieldsParams &rhs);
-
-    PosOccFieldsParams &operator=(const PosOccFieldsParams &rhs);
-    bool operator==(const PosOccFieldsParams &rhs) const;
-
-    void cacheParamsRef() {
-        _numFields = _params.size();
-        _fieldParams = _params.empty() ? nullptr : &_params[0];
-    }
-
-    void assertCachedParamsRef() const {
-        assert(_numFields == _params.size());
-        assert(_fieldParams == (_params.empty() ? nullptr : &_params[0]));
-    }
-
-    uint32_t getNumFields() const { return _numFields; }
-    const PosOccFieldParams *getFieldParams() const { return _fieldParams; }
-    void getParams(PostingListParams &params) const;
-    void setParams(const PostingListParams &params);
-    void setSchemaParams(const Schema &schema, const uint32_t indexId);
-    void readHeader(const vespalib::GenericHeader &header, const vespalib::string &prefix);
-    void writeHeader(vespalib::GenericHeader &header, const vespalib::string &prefix) const;
-};
+class PosOccFieldsParams;
 
 template <bool bigEndian>
 class EG2PosOccDecodeContext : public FeatureDecodeContext<bigEndian>
diff --git a/searchlib/src/vespa/searchlib/diskindex/zcposocc.h b/searchlib/src/vespa/searchlib/diskindex/zcposocc.h
index 1e0555116ce..27700399bfb 100644
--- a/searchlib/src/vespa/searchlib/diskindex/zcposocc.h
+++ b/searchlib/src/vespa/searchlib/diskindex/zcposocc.h
@@ -4,6 +4,7 @@
 
 #include "zcposting.h"
 #include <vespa/searchlib/bitcompression/posocccompression.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 
 namespace search::diskindex {
 
diff --git a/searchlib/src/vespa/searchlib/diskindex/zcposocciterators.cpp b/searchlib/src/vespa/searchlib/diskindex/zcposocciterators.cpp
index 6a3ea9254d2..b71a1505eac 100644
--- a/searchlib/src/vespa/searchlib/diskindex/zcposocciterators.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/zcposocciterators.cpp
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "zcposocciterators.h"
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 #include <vespa/searchlib/fef/termfieldmatchdata.h>
 #include "zc4_posting_params.h"
 
diff --git a/searchlib/src/vespa/searchlib/diskindex/zcposoccrandread.h b/searchlib/src/vespa/searchlib/diskindex/zcposoccrandread.h
index dcaca5d1f81..26b23161cb1 100644
--- a/searchlib/src/vespa/searchlib/diskindex/zcposoccrandread.h
+++ b/searchlib/src/vespa/searchlib/diskindex/zcposoccrandread.h
@@ -5,6 +5,7 @@
 #include <vespa/searchlib/index/postinglistfile.h>
 #include <vespa/searchlib/bitcompression/compression.h>
 #include <vespa/searchlib/bitcompression/posocccompression.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 #include <vespa/searchlib/fef/termfieldmatchdataarray.h>
 #include "zc4_posting_params.h"
 
diff --git a/searchlib/src/vespa/searchlib/memoryindex/feature_store.h b/searchlib/src/vespa/searchlib/memoryindex/feature_store.h
index 6afc3c02301..59683d30c1f 100644
--- a/searchlib/src/vespa/searchlib/memoryindex/feature_store.h
+++ b/searchlib/src/vespa/searchlib/memoryindex/feature_store.h
@@ -5,6 +5,7 @@
 #include <vespa/searchlib/index/docidandfeatures.h>
 #include <vespa/searchlib/bitcompression/compression.h>
 #include <vespa/searchlib/bitcompression/posocccompression.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 #include <vespa/vespalib/datastore/datastore.h>
 
 namespace search::memoryindex {
diff --git a/searchlib/src/vespa/searchlib/test/fakedata/fakeword.cpp b/searchlib/src/vespa/searchlib/test/fakedata/fakeword.cpp
index 641398f8ae1..e40cfd1748c 100644
--- a/searchlib/src/vespa/searchlib/test/fakedata/fakeword.cpp
+++ b/searchlib/src/vespa/searchlib/test/fakedata/fakeword.cpp
@@ -7,6 +7,7 @@
 #include <vespa/searchlib/index/docidandfeatures.h>
 #include <vespa/searchlib/bitcompression/compression.h>
 #include <vespa/searchlib/bitcompression/posocccompression.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 
 using search::fef::TermFieldMatchData;
 using search::fef::TermFieldMatchDataPosition;
diff --git a/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.cpp b/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.cpp
index 09c8e86d979..1be2ea65796 100644
--- a/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.cpp
+++ b/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.cpp
@@ -3,6 +3,7 @@
 #include "fakewordset.h"
 #include "fakeword.h"
 #include <vespa/fastos/time.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 #include <sstream>
 
 #include <vespa/log/log.h>
diff --git a/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.h b/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.h
index d404c664a34..3dcf47cf8c8 100644
--- a/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.h
+++ b/searchlib/src/vespa/searchlib/test/fakedata/fakewordset.h
@@ -4,6 +4,7 @@
 #include <vector>
 #include <vespa/searchlib/bitcompression/compression.h>
 #include <vespa/searchlib/bitcompression/posocccompression.h>
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 
 namespace search { class Rand48; }
 
diff --git a/searchlib/src/vespa/searchlib/test/fakedata/fakezcfilterocc.cpp b/searchlib/src/vespa/searchlib/test/fakedata/fakezcfilterocc.cpp
index ac2c0203ac8..f4189d0ce66 100644
--- a/searchlib/src/vespa/searchlib/test/fakedata/fakezcfilterocc.cpp
+++ b/searchlib/src/vespa/searchlib/test/fakedata/fakezcfilterocc.cpp
@@ -2,6 +2,7 @@
 
 #include "fakezcfilterocc.h"
 #include "fpfactory.h"
+#include <vespa/searchlib/bitcompression/posocc_fields_params.h>
 #include <vespa/searchlib/diskindex/zcposocciterators.h>
 #include <vespa/searchlib/diskindex/zc4_posting_header.h>
 #include <vespa/searchlib/diskindex/zc4_posting_params.h>