java.lang.Object
- deltix.qsrv.hf.pub.codec.SchemaComparator

```
public abstract class SchemaComparator
extends java.lang.Object
```
Utilities for comparing two record descriptors in order to determine whether messages serialized with one can be deserialized with another.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class SchemaComparator.Listener

Field Summary

Fields
Modifier and Type	Field	Description
`static long`	`DETECT_ALL_CHANGES`	Detect all changes that affect non-static fields, except annotations such as titles or primary keys (ignore nothing).
`static long`	`DETECT_ONLY_STRUCTURAL_INCOMPATIBILITY`	Detect only those changes that cause structural incompatibility between two schemas, ignoring name changes, and anything else unless it is guaranteed to make the schemas incompatible.
`static SchemaComparator.Listener`	`DUMMY_LISTENER`
`static long`	`IGNORE_BINDING_CHANGE`	Ignore changed bound class names.
`static long`	`IGNORE_CLASS_NAME_CHANGE`	Ignore changed class names, as long as their internal structure remains compatible.
`static long`	`IGNORE_ENUM_EXTENSION`	Ignore the extention of enumerated types.
`static long`	`IGNORE_ENUM_NAME_CHANGE`	Ignore changed enum constant names.
`static long`	`IGNORE_ENUM_REDUCTION`	Ignore the reduction of enumerated types.
`static long`	`IGNORE_FIELD_NAME_CHANGE`	Ignore changed field names, as long as their types and encodings remain compatible.
`static long`	`IGNORE_HIERARCHY_CHANGE`	Ignore changes in class hierarchy, as long as all fields are in the same order.
`static long`	`IGNORE_RANGE_NARROWING`	Ignore the narrowing of numeric value ranges.

Constructor Summary

Constructors
Constructor Description

SchemaComparator()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static boolean`	`schemaChanged(long options, RecordClassDescriptor old, RecordClassDescriptor nw)`	Same as `schemaChanged(long, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.codec.SchemaComparator.Listener)` invoked with a null listener.
`static boolean`	`schemaChanged(long options, RecordClassDescriptor old, RecordClassDescriptor nw, SchemaComparator.Listener listener)`	Compare two record descriptors in order to determine whether messages serialized with one can be deserialized with another.
`static boolean`	`schemaChanged(RecordClassDescriptor old, RecordClassDescriptor nw, SchemaComparator.Listener listener)`	Same as `schemaChanged(long, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.codec.SchemaComparator.Listener)` invoked with all ignore options, i.e. it will return true only if the schema change is guaranteed

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DETECT_ONLY_STRUCTURAL_INCOMPATIBILITY
```
public static final long DETECT_ONLY_STRUCTURAL_INCOMPATIBILITY
```
    Detect only those changes that cause structural incompatibility between two schemas, ignoring name changes, and anything else unless it is guaranteed to make the schemas incompatible.
    
    See Also:
    
    Constant Field Values
  - DETECT_ALL_CHANGES
```
public static final long DETECT_ALL_CHANGES
```
    Detect all changes that affect non-static fields, except annotations such as titles or primary keys (ignore nothing).
    
    See Also:
    
    Constant Field Values
  - IGNORE_FIELD_NAME_CHANGE
```
public static final long IGNORE_FIELD_NAME_CHANGE
```
    Ignore changed field names, as long as their types and encodings remain compatible.
    
    See Also:
    
    Constant Field Values
  - IGNORE_CLASS_NAME_CHANGE
```
public static final long IGNORE_CLASS_NAME_CHANGE
```
    Ignore changed class names, as long as their internal structure remains compatible.
    
    See Also:
    
    Constant Field Values
  - IGNORE_ENUM_NAME_CHANGE
```
public static final long IGNORE_ENUM_NAME_CHANGE
```
    Ignore changed enum constant names.
    
    See Also:
    
    Constant Field Values
  - IGNORE_ENUM_EXTENSION
```
public static final long IGNORE_ENUM_EXTENSION
```
    Ignore the extention of enumerated types.
    
    See Also:
    
    Constant Field Values
  - IGNORE_ENUM_REDUCTION
```
public static final long IGNORE_ENUM_REDUCTION
```
    Ignore the reduction of enumerated types.
    
    See Also:
    
    Constant Field Values
  - IGNORE_RANGE_NARROWING
```
public static final long IGNORE_RANGE_NARROWING
```
    Ignore the narrowing of numeric value ranges.
    
    See Also:
    
    Constant Field Values
  - IGNORE_BINDING_CHANGE
```
public static final long IGNORE_BINDING_CHANGE
```
    Ignore changed bound class names.
    
    See Also:
    
    Constant Field Values
  - IGNORE_HIERARCHY_CHANGE
```
public static final long IGNORE_HIERARCHY_CHANGE
```
    Ignore changes in class hierarchy, as long as all fields are in the same order.
    
    See Also:
    
    Constant Field Values
  - DUMMY_LISTENER
```
public static final SchemaComparator.Listener DUMMY_LISTENER
```
- Constructor Detail
  - SchemaComparator
```
public SchemaComparator()
```
- Method Detail
  - schemaChanged
```
public static boolean schemaChanged(long options,
                                    RecordClassDescriptor old,
                                    RecordClassDescriptor nw,
                                    SchemaComparator.Listener listener)
```
    Compare two record descriptors in order to determine whether messages serialized with one can be deserialized with another. Most changes make serialized data at least potentially incompatible. Exceptions include changed field titles or extended value ranges. Some changes make data completely incompatible, such as changed sequence of data types, or incompatible encoding changes. This utility always ignores static fields, because it is concerned with serialized data only. Also, this utility ignores the "primary key" attribute for the same reasons.
    
    Parameters:
    
    options - A bitwise combination of IGNORE_ options.
    
    old - Old record descriptor (presumably describing some data that is already serialized).
    
    nw - New look of the same record descriptor, considered for potential deserialization of the same data.
    
    listener - Gets notified about discrepancies. Can be null.
    
    Returns:
    
    Whether any relevant changes have been observed, except those ignored according to the specified flags.
  - schemaChanged
```
public static boolean schemaChanged(long options,
                                    RecordClassDescriptor old,
                                    RecordClassDescriptor nw)
```
    Same as schemaChanged(long, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.codec.SchemaComparator.Listener) invoked with a null listener.
  - schemaChanged
```
public static boolean schemaChanged(RecordClassDescriptor old,
                                    RecordClassDescriptor nw,
                                    SchemaComparator.Listener listener)
```
    Same as schemaChanged(long, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.md.RecordClassDescriptor, deltix.qsrv.hf.pub.codec.SchemaComparator.Listener) invoked with all ignore options, i.e. it will return true only if the schema change is guaranteed

Class SchemaComparator

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DETECT_ONLY_STRUCTURAL_INCOMPATIBILITY

DETECT_ALL_CHANGES

IGNORE_FIELD_NAME_CHANGE

IGNORE_CLASS_NAME_CHANGE

IGNORE_ENUM_NAME_CHANGE

IGNORE_ENUM_EXTENSION

IGNORE_ENUM_REDUCTION

IGNORE_RANGE_NARROWING

IGNORE_BINDING_CHANGE

IGNORE_HIERARCHY_CHANGE

DUMMY_LISTENER

Constructor Detail

SchemaComparator

Method Detail

schemaChanged

schemaChanged

schemaChanged