org.apache.tomcat.util.http
Class MimeHeaders
public
class
MimeHeaders
extends Object
Memory-efficient repository for Mime Headers. When the object is recycled, it
will keep the allocated headers[] and all the MimeHeaderField - no GC is generated.
For input headers it is possible to use the MessageByte for Fileds - so no GC
will be generated.
The only garbage is generated when using the String for header names/values -
this can't be avoided when the servlet calls header methods, but is easy
to avoid inside tomcat. The goal is to use _only_ MessageByte-based Fields,
and reduce to 0 the memory overhead of tomcat.
TODO:
XXX one-buffer parsing - for http ( other protocols don't need that )
XXX remove unused methods
XXX External enumerations, with 0 GC.
XXX use HeaderName ID
Author: dac@eng.sun.com James Todd [gonzo@eng.sun.com] Costin Manolache kevin seguin
Field Summary |
static int | DEFAULT_HEADER_SIZE Initial size - should be == average number of headers per request
XXX make it configurable ( fine-tuning of web-apps ) |
Method Summary |
MessageBytes | addValue(String name) Create a new named header , return the MessageBytes
container for the new value |
MessageBytes | addValue(byte[] b, int startN, int len) Create a new named header using un-translated byte[].
|
MessageBytes | addValue(char[] c, int startN, int len) Create a new named header using translated char[]. |
void | clear()
Clears all header fields. |
int | findHeader(String name, int starting) Find the index of a header with the given name. |
String | getHeader(String name) |
MessageBytes | getName(int n)
Returns the Nth header name, or null if there is no such header.
|
MessageBytes | getUniqueValue(String name)
Finds and returns a unique header field with the given name. |
MessageBytes | getValue(int n)
Returns the Nth header value, or null if there is no such header.
|
MessageBytes | getValue(String name)
Finds and returns a header field with the given name. |
Enumeration | names()
Returns an enumeration of strings representing the header field names.
|
void | recycle()
Clears all header fields. |
void | removeHeader(String name)
Removes a header field with the specified name. |
MessageBytes | setValue(String name) Allow "set" operations -
return a MessageBytes container for the
header value ( existing header or new
if this . |
int | size()
Returns the current number of header fields. |
String | toString()
EXPENSIVE! |
Enumeration | values(String name) |
public static final int DEFAULT_HEADER_SIZE
Initial size - should be == average number of headers per request
XXX make it configurable ( fine-tuning of web-apps )
public MimeHeaders()
Creates a new MimeHeaders object using a default buffer size.
Create a new named header , return the MessageBytes
container for the new value
Create a new named header using un-translated byte[].
The conversion to chars can be delayed until
encoding is known.
Create a new named header using translated char[].
public void clear()
Clears all header fields.
public int findHeader(String name, int starting)
Find the index of a header with the given name.
public String getHeader(String name)
Returns the Nth header name, or null if there is no such header.
This may be used to iterate through all header fields.
Finds and returns a unique header field with the given name. If no such
field exists, null is returned. If the specified header field is not
unique then an IllegalArgumentException is thrown.
Returns the Nth header value, or null if there is no such header.
This may be used to iterate through all header fields.
Finds and returns a header field with the given name. If no such
field exists, null is returned. If more than one such field is
in the header, an arbitrary one is returned.
public Enumeration names()
Returns an enumeration of strings representing the header field names.
Field names may appear multiple times in this enumeration, indicating
that multiple fields with that name exist in this header.
public void recycle()
Clears all header fields.
public void removeHeader(String name)
Removes a header field with the specified name. Does nothing
if such a field could not be found.
Parameters: name the name of the header field to be removed
Allow "set" operations -
return a MessageBytes container for the
header value ( existing header or new
if this .
public int size()
Returns the current number of header fields.
public String toString()
EXPENSIVE!!! only for debugging.
public Enumeration values(String name)
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