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authorMatt A. Tobin <email@mattatobin.com>2019-11-03 00:17:46 -0400
committerMatt A. Tobin <email@mattatobin.com>2019-11-03 00:17:46 -0400
commit302bf1b523012e11b60425d6eee1221ebc2724eb (patch)
treeb191a895f8716efcbe42f454f37597a545a6f421 /mailnews/base/util/nsMsgCompressIStream.cpp
parent21b3f6247403c06f85e1f45d219f87549862198f (diff)
downloaduxp-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.cpp228
1 files changed, 228 insertions, 0 deletions
diff --git a/mailnews/base/util/nsMsgCompressIStream.cpp b/mailnews/base/util/nsMsgCompressIStream.cpp
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index 0000000000..5b47422f29
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+++ b/mailnews/base/util/nsMsgCompressIStream.cpp
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+/* 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;
+}
+