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Class grendel.storage.MailSummaryFile
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Class grendel.storage.MailSummaryFile
java.lang.Object
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+----grendel.storage.MailSummaryFile
abstract class MailSummaryFile
extends java.lang.Object
{
// Fields 9
protected long deleted_message_bytes;
protected File file;
protected long file_date;
protected long file_size;
protected BerkeleyFolder folder;
protected Hashtable salvage;
protected int total_message_count;
protected int undeleted_message_count;
protected int unread_message_count;
// Constructors 1
MailSummaryFile(BerkeleyFolder);
// Methods 25
protected boolean checkFolderDate(long);
protected boolean checkFolderSize(long);
long deletedMessageBytes();
long folderDate();
long folderSize();
protected abstract void getMessageCounts();
abstract long readSummaryFile(InputStream) throws IOException;
protected synchronized long readUnsignedInteger(InputStream) throws IOException;
protected synchronized long readUnsignedInteger(RandomAccessFile) throws IOException;
protected synchronized int readUnsignedShort(InputStream) throws IOException;
protected synchronized int readUnsignedShort(RandomAccessFile) throws IOException;
protected void salvageMessage(BerkeleyMessage, Object);
void salvageMessages();
void setFolderDateAndSize(long, long);
void setFolderMessageCounts(int, int, int, long);
int totalMessageCount();
int undeletedMessageCount();
int unreadMessageCount();
void updateSummaryFile() throws IOException;
boolean writable();
void writeSummaryFile() throws IOException;
protected synchronized void writeUnsignedInteger(OutputStream, long) throws IOException;
protected synchronized void writeUnsignedInteger(RandomAccessFile, long) throws IOException;
protected synchronized void writeUnsignedShort(OutputStream, int) throws IOException;
protected synchronized void writeUnsignedShort(RandomAccessFile, int) throws IOException;
}
Fields
protected BerkeleyFolder folder
The folder and associated disk file. The file might not exist.
protected File file
protected long file_date
protected long file_size
protected int total_message_count
protected int undeleted_message_count
protected int unread_message_count
protected long deleted_message_bytes
protected Hashtable salvage
For salvageMessages(). If the table is non-null, its keys will be
MessageID objects, and the values will be opaque objects intended
to be passed to salvageMessageSummary(). Subclasses are responsible
for populating this table, if they are able.
Constructors
MailSummaryFile(BerkeleyFolder f)
Methods
abstract long readSummaryFile(InputStream sum) throws IOException
Parses a summary file for the associated folder, and adds the described
message objects to the folder. The given stream is assumed to have
been opened, and positioned past any version-identifying header info.
Returns the byte position at which parsing should resume (that is, the
last byte position which the summary file summarizes.)
boolean writable()
Whether this class knows how to write a summary file.
void writeSummaryFile() throws IOException
Write a summary file for the associated folder. If a subclass provides
an implementation for this method, it should also override writable().
long folderDate()
Returns the date that the summary file expects to find on the
folder's file. This is measured in the units of File.lastModified().
Set this expectation with setFolderDateAndSize().
long folderSize()
Returns the size in bytes that the summary file expects of the
folder's file. Set this expectation with setFolderDateAndSize().
int totalMessageCount()
Returns the total number of messages in the folder.
This includes deleted and unread messages.
int undeletedMessageCount()
Returns the number of non-deleted messages in the folder.
This includes unread messages.
int unreadMessageCount()
Returns the number of unread messages in the folder.
This does not include unread messages that are also deleted.
long deletedMessageBytes()
Returns the number of bytes consumed by deleted but not expunged
messages in the folder.
protected abstract void getMessageCounts()
Read only enough of the file to fill in the values of
total_message_count, undeleted_message_count, unread_message_count,
and deleted_message_bytes.
void setFolderDateAndSize(long file_date,
long file_size)
Set the date and size of the corresponding folder-file.
This date/time pair should correspond to the file at the time at
which it was parsed, not the current time.
The next time writeSummaryFile() is called, the new summary
file will encode this date and size expectation.
void setFolderMessageCounts(int total_count,
int undeleted_count,
int unread_count,
long deleted_bytes)
Set the message counts (total, undeleted, and unread) of the
corresponding folder-file. The next time writeSummaryFile() is
called, the new summary file will include these numbers.
| Parameter | Description |
| total_count | The total number of messages in the folder.
This must match the number of elements returned
by getMessages() at the time that
writeSummaryFile() is called. |
| undeleted_count | The total number of messages in the folder
that are not marked as deleted. This also
must match reality when writeSummaryFile() is
called. |
| unread_count | The total number of messages in the folder
that are not marked as either read or deleted.
Ditto writeSummaryFile(). |
| deleted_bytes | The total number of bytes consumed by messages
that are marked as deleted.
Ditto writeSummaryFile(). |
void updateSummaryFile() throws IOException
Called when the folder's disk file has been appended to by *this*
program. (As opposed to, an unexpected, unknown change by some other
program.) This calls setFolderDateAndSize() with the current date
and size of the folder file (as it appears on disk right now.)
If the number of messages has changed, you should have called
setFolderMessageCounts() before calling this.
protected boolean checkFolderDate(long summary_date)
Compare the date of the folder disk file to a date (presumably) read
from the summary file, and return true of they are equal.
protected boolean checkFolderSize(long summary_size)
Compare the size of the folder disk file to a size (presumably) read
from the summary file, and return true of they are equal.
void salvageMessages()
Call this if something has gone wrong when parsing the summary file,
but after the folder file has been parsed. This might cause
some additional information to be scavenged from the summary file
and stored into the messages.
The idea here is that an out-of-date summary file cannot be
trusted as far as byte-offsets and such goes, but if the summary
file had stored some property of a message (such as whether it was
deleted) then we might as well believe that, lacking any other
source of information.
Note that one folder can contain multiple messages with the same
ID, so this process is not totally foolproof. It is, however,
better than nothing.
protected void salvageMessage(BerkeleyMessage m,
Object salvage_object)
protected synchronized int readUnsignedShort(InputStream s) throws IOException
protected synchronized long readUnsignedInteger(InputStream s) throws IOException
protected synchronized void writeUnsignedShort(OutputStream s,
int i) throws IOException
protected synchronized void writeUnsignedInteger(OutputStream s,
long i) throws IOException
protected synchronized int readUnsignedShort(RandomAccessFile s) throws IOException
protected synchronized long readUnsignedInteger(RandomAccessFile s) throws IOException
protected synchronized void writeUnsignedShort(RandomAccessFile s,
int i) throws IOException
protected synchronized void writeUnsignedInteger(RandomAccessFile s,
long i) throws IOException
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