Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef COMM_MAILNEWS_BASE_SRC_MBOXMSGINPUTSTREAM_H_
#define COMM_MAILNEWS_BASE_SRC_MBOXMSGINPUTSTREAM_H_
#include "nsIInputStream.h"
#include "nsCOMPtr.h"
#include "mozilla/Buffer.h"
#include "mozilla/Mutex.h"
class MboxParser;
/**
* MboxMsgInputStream reads messages from an underlying mbox stream. Messages
* will be read in sequence beginning at the position of the underlying stream,
* returning EOF at the end of each message. Subsequent messages can be read by
* calling `Continue()`.
*
* Escaped ">From " lines in the body of the message will be silently
* unescaped. The caller should never need to deal with (or be aware of)
* escaping.
*
* The underlying stream is expected to be pre-positioned at the beginning of
* the "From " line indicating a new message.
*
* MboxMsgInputStream should be regarded as taking ownership of the
* underlying stream: when the MboxMsgInputStream is closed, the underlying
* stream is also closed.
*/
class MboxMsgInputStream : public nsIInputStream {
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
/**
* mboxStream is a stream for reading the raw mbox data, positioned at the
* "From " line.
* MboxMsgInputStream assumes ownership of mboxStream, and will close it
* when done.
* When a non-zero maxAllowedSize is given, read at most this amount of
* bytes from the stream.
* The maxAllowedSize parameter allows the caller to specify a safety limit,
* if it knows that the number of expected bytes is smaller than the
* given number. This is useful if the mbox stream doesn't contain the
* expected separators.
*/
explicit MboxMsgInputStream(nsIInputStream* mboxStream,
uint32_t maxAllowedSize);
MboxMsgInputStream() = delete;
/**
* A null message is an empty message where there isn't even a "From "
* separator line, most likely due to an empty mbox file.
* It's a bit of an icky special case, but we'll use this when doing an
* async scan over an empty mbox file without returning a spurious empty
* message - see MboxScanner, in nsMsgBrkMBoxStore.cpp.
*/
bool IsNullMessage();
/**
* Start reading the next message, if any. Think of it as a "reopen".
* The stream must have been completely exhausted to EOF (by calling Read())
* before Continue() can be called.
* If no more messages are available (i.e. we've hit the end of the mbox),
* then `more` will contain false upon return.
*
* Continue() will fail if stream has been closed.
* This is because Close() also closes the underlying stream.
*/
nsresult Continue(bool& more);
/**
* Return the offset at which the current message is located. This would be
* the location of the "From " separator line.
* NOTE: this value is relative to where the underlying stream was
* positioned when the MboxMsgInputStream was constructed!
* If a seek was performed beforehand, that position is considered offset 0.
*/
uint64_t MsgOffset();
/**
* If the "From " line contained a sender, it can be accessed here.
* Otherwise an empty string will be returned.
*/
nsCString EnvAddr();
/**
* If the "From " line contained a timestamp, it can be accessed here.
* Otherwise 0 will be returned.
*/
PRTime EnvDate();
protected:
virtual ~MboxMsgInputStream();
nsresult PumpData();
// The underlying mbox stream we're parsing.
nsCOMPtr<nsIInputStream> mRawStream;
nsresult mStatus;
// Our input buffer.
mozilla::Buffer<char> mBuf;
// Number of consumed bytes in mBuf (starting from position 0).
size_t mUsed;
// Number of unconsumed bytes in mBuf (starting at position mUsed).
size_t mUnused;
// Total bytes consumed from mbox file so far.
uint64_t mTotalUsed;
// The offset at which the current message began.
uint64_t mMsgOffset;
uint32_t mLimitOutputBytes;
uint32_t mOutputBytes;
bool mOverflow;
// Hide gory parsing details with pIMPL.
mozilla::UniquePtr<MboxParser> mParser;
private:
mozilla::Mutex mLock;
};
#endif // COMM_MAILNEWS_BASE_SRC_MBOXMSGINPUTSTREAM_H_