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author | Matt A. Tobin <email@mattatobin.com> | 2019-11-03 00:17:46 -0400 |
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committer | Matt A. Tobin <email@mattatobin.com> | 2019-11-03 00:17:46 -0400 |
commit | 302bf1b523012e11b60425d6eee1221ebc2724eb (patch) | |
tree | b191a895f8716efcbe42f454f37597a545a6f421 /mailnews/base/util/nsMsgCompressIStream.cpp | |
parent | 21b3f6247403c06f85e1f45d219f87549862198f (diff) | |
download | uxp-302bf1b523012e11b60425d6eee1221ebc2724eb.tar.gz |
Issue #1258 - Part 1: Import mailnews, ldap, and mork from comm-esr52.9.1
Diffstat (limited to 'mailnews/base/util/nsMsgCompressIStream.cpp')
-rw-r--r-- | mailnews/base/util/nsMsgCompressIStream.cpp | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/mailnews/base/util/nsMsgCompressIStream.cpp b/mailnews/base/util/nsMsgCompressIStream.cpp new file mode 100644 index 0000000000..5b47422f29 --- /dev/null +++ b/mailnews/base/util/nsMsgCompressIStream.cpp @@ -0,0 +1,228 @@ +/* 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 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsMsgCompressIStream.h" +#include "prio.h" +#include "prmem.h" +#include "nsAlgorithm.h" +#include <algorithm> + +#define BUFFER_SIZE 16384 + +nsMsgCompressIStream::nsMsgCompressIStream() : + m_dataptr(nullptr), + m_dataleft(0), + m_inflateAgain(false) +{ +} + +nsMsgCompressIStream::~nsMsgCompressIStream() +{ + Close(); +} + +NS_IMPL_ISUPPORTS(nsMsgCompressIStream, nsIInputStream, + nsIAsyncInputStream) + +nsresult nsMsgCompressIStream::InitInputStream(nsIInputStream *rawStream) +{ + // protect against repeat calls + if (m_iStream) + return NS_ERROR_UNEXPECTED; + + // allocate some memory for buffering + m_zbuf = mozilla::MakeUnique<char[]>(BUFFER_SIZE); + if (!m_zbuf) + return NS_ERROR_OUT_OF_MEMORY; + + // allocate some memory for buffering + m_databuf = mozilla::MakeUnique<char[]>(BUFFER_SIZE); + if (!m_databuf) + return NS_ERROR_OUT_OF_MEMORY; + + // set up zlib object + m_zstream.zalloc = Z_NULL; + m_zstream.zfree = Z_NULL; + m_zstream.opaque = Z_NULL; + + // http://zlib.net/manual.html is rather silent on the topic, but + // perl's Compress::Raw::Zlib manual says: + // -WindowBits + // To compress an RFC 1951 data stream, set WindowBits to -MAX_WBITS. + if (inflateInit2(&m_zstream, -MAX_WBITS) != Z_OK) + return NS_ERROR_FAILURE; + + m_iStream = rawStream; + + return NS_OK; +} + +nsresult nsMsgCompressIStream::DoInflation() +{ + // if there's something in the input buffer of the zstream, process it. + m_zstream.next_out = (Bytef *) m_databuf.get(); + m_zstream.avail_out = BUFFER_SIZE; + int zr = inflate(&m_zstream, Z_SYNC_FLUSH); + + // inflate() should normally be called until it returns + // Z_STREAM_END or an error, and Z_BUF_ERROR just means + // unable to progress any further (possible if we filled + // an output buffer exactly) + if (zr == Z_BUF_ERROR || zr == Z_STREAM_END) + zr = Z_OK; + + // otherwise it's an error + if (zr != Z_OK) + return NS_ERROR_FAILURE; + + // http://www.zlib.net/manual.html says: + // If inflate returns Z_OK and with zero avail_out, it must be called + // again after making room in the output buffer because there might be + // more output pending. + m_inflateAgain = m_zstream.avail_out ? false : true; + + // set the pointer to the start of the buffer, and the count to how + // based on how many bytes are left unconsumed. + m_dataptr = m_databuf.get(); + m_dataleft = BUFFER_SIZE - m_zstream.avail_out; + + return NS_OK; +} + +/* void close (); */ +NS_IMETHODIMP nsMsgCompressIStream::Close() +{ + return CloseWithStatus(NS_OK); +} + +NS_IMETHODIMP nsMsgCompressIStream::CloseWithStatus(nsresult reason) +{ + nsresult rv = NS_OK; + + if (m_iStream) + { + // pass the status through to our wrapped stream + nsCOMPtr <nsIAsyncInputStream> asyncInputStream = do_QueryInterface(m_iStream); + if (asyncInputStream) + rv = asyncInputStream->CloseWithStatus(reason); + + // tidy up + m_iStream = nullptr; + inflateEnd(&m_zstream); + } + + // clean up all the buffers + m_zbuf = nullptr; + m_databuf = nullptr; + m_dataptr = nullptr; + m_dataleft = 0; + + return rv; +} + +/* unsigned long long available (); */ +NS_IMETHODIMP nsMsgCompressIStream::Available(uint64_t *aResult) +{ + if (!m_iStream) + return NS_BASE_STREAM_CLOSED; + + // check if there's anything still in flight + if (!m_dataleft && m_inflateAgain) + { + nsresult rv = DoInflation(); + NS_ENSURE_SUCCESS(rv, rv); + } + + // we'll be returning this many to the next read, guaranteed + if (m_dataleft) + { + *aResult = m_dataleft; + return NS_OK; + } + + // this value isn't accurate, but will give a good true/false + // indication for idle purposes, and next read will fill + // m_dataleft, so we'll have an accurate count for the next call. + return m_iStream->Available(aResult); +} + +/* [noscript] unsigned long read (in charPtr aBuf, in unsigned long aCount); */ +NS_IMETHODIMP nsMsgCompressIStream::Read(char * aBuf, uint32_t aCount, uint32_t *aResult) +{ + if (!m_iStream) + { + *aResult = 0; + return NS_OK; + } + + // There are two stages of buffering: + // * m_zbuf contains the compressed data from the remote server + // * m_databuf contains the uncompressed raw bytes for consumption + // by the local client. + // + // Each buffer will only be filled when the following buffers + // have been entirely consumed. + // + // m_dataptr and m_dataleft are respectively a pointer to the + // unconsumed portion of m_databuf and the number of bytes + // of uncompressed data remaining in m_databuf. + // + // both buffers have a maximum size of BUFFER_SIZE, so it is + // possible that multiple inflate passes will be required to + // consume all of m_zbuf. + while (!m_dataleft) + { + // get some more data if we don't already have any + if (!m_inflateAgain) + { + uint32_t bytesRead; + nsresult rv = m_iStream->Read(m_zbuf.get(), (uint32_t)BUFFER_SIZE, &bytesRead); + NS_ENSURE_SUCCESS(rv, rv); + if (!bytesRead) + return NS_BASE_STREAM_CLOSED; + m_zstream.next_in = (Bytef *) m_zbuf.get(); + m_zstream.avail_in = bytesRead; + } + + nsresult rv = DoInflation(); + NS_ENSURE_SUCCESS(rv, rv); + } + + *aResult = std::min(m_dataleft, aCount); + + if (*aResult) + { + memcpy(aBuf, m_dataptr, *aResult); + m_dataptr += *aResult; + m_dataleft -= *aResult; + } + + return NS_OK; +} + +/* [noscript] unsigned long readSegments (in nsWriteSegmentFun aWriter, in voidPtr aClosure, in unsigned long aCount); */ +NS_IMETHODIMP nsMsgCompressIStream::ReadSegments(nsWriteSegmentFun aWriter, void * aClosure, uint32_t aCount, uint32_t *_retval) +{ + return NS_ERROR_NOT_IMPLEMENTED; +} + +NS_IMETHODIMP nsMsgCompressIStream::AsyncWait(nsIInputStreamCallback *callback, uint32_t flags, uint32_t amount, nsIEventTarget *target) +{ + if (!m_iStream) + return NS_BASE_STREAM_CLOSED; + + nsCOMPtr <nsIAsyncInputStream> asyncInputStream = do_QueryInterface(m_iStream); + if (asyncInputStream) + return asyncInputStream->AsyncWait(callback, flags, amount, target); + + return NS_OK; +} + +/* boolean isNonBlocking (); */ +NS_IMETHODIMP nsMsgCompressIStream::IsNonBlocking(bool *aNonBlocking) +{ + *aNonBlocking = false; + return NS_OK; +} + |