On 06.10.2020 9:34, Andrey M. Borodin wrote:
26 марта 2019 г., в 19:46, Konstantin Knizhnik <k.knizh...@postgrespro.ru>
написал(а):
Version of the patch correctly working when no compression algorithm are
avaiable.
Thanks for this work, Konstantin.
PFA rebased version of this patch.
This compression seems very important to reduce network-induced replication lag.
Recently I've found out that small installation suffer from huge latency spike
when archive_timeout occurs.
How this happens? archive_timeout emits segment switch, which pads current
segment with zeroes. Now these zeroes need to be replicated to standbys,
without compression. Transfer of zeroes causes long waits for synchronous
replication (up to 1s with network restricted to 16Mbps).
Also replication compression will reduce overall cross-AZ traffic of HA
installations.
So I'm considering following plan for 2020: implement this protocol in Odyssey
and send patches to drivers to enable early access to this feature.
Best regards, Andrey Borodin.
Rebased version of the patch is attached.
I am going to resubmit it to the next CF.
diff --git a/configure b/configure
index 071d050..12ae2dd 100755
--- a/configure
+++ b/configure
@@ -700,6 +700,7 @@ LD
LDFLAGS_SL
LDFLAGS_EX
with_zlib
+with_zstd
with_system_tzdata
with_libxslt
XML2_LIBS
@@ -867,6 +868,7 @@ with_libxml
with_libxslt
with_system_tzdata
with_zlib
+with_zstd
with_gnu_ld
enable_largefile
'
@@ -8571,6 +8573,85 @@ fi
+#
+# ZStd
+#
+
+
+
+# Check whether --with-zstd was given.
+if test "${with_zstd+set}" = set; then :
+ withval=$with_zstd;
+ case $withval in
+ yes)
+ ;;
+ no)
+ :
+ ;;
+ *)
+ as_fn_error $? "no argument expected for --with-zstd option" "$LINENO" 5
+ ;;
+ esac
+
+else
+ with_zstd=no
+
+fi
+
+
+
+
+if test "$with_zstd" = yes ; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ZSTD_compress in -lzstd" >&5
+$as_echo_n "checking for ZSTD_compress in -lzstd... " >&6; }
+if ${ac_cv_lib_zstd_ZSTD_compress+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_check_lib_save_LIBS=$LIBS
+LIBS="-lzstd $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+/* Override any GCC internal prototype to avoid an error.
+ Use char because int might match the return type of a GCC
+ builtin and then its argument prototype would still apply. */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ZSTD_compress ();
+int
+main ()
+{
+return ZSTD_compress ();
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ ac_cv_lib_zstd_ZSTD_compress=yes
+else
+ ac_cv_lib_zstd_ZSTD_compress=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_zstd_ZSTD_compress" >&5
+$as_echo "$ac_cv_lib_zstd_ZSTD_compress" >&6; }
+if test "x$ac_cv_lib_zstd_ZSTD_compress" = xyes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBZSTD 1
+_ACEOF
+
+ LIBS="-lzstd $LIBS"
+
+else
+ as_fn_error $? "library 'zstd' is required for ZSTD support" "$LINENO" 5
+fi
+
+fi
+
+
#
# Zlib
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index de60281..4a1f49c 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1225,6 +1225,20 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
</listitem>
</varlistentry>
+ <varlistentry id="libpq-connect-compression" xreflabel="compression">
+ <term><literal>compression</literal></term>
+ <listitem>
+ <para>
+ Request compression of libpq traffic. Client sends to the server list of compression algorithms, supported by client library.
+ If server supports one of this algorithms, then it acknowledges use of this algorithm and then all libpq messages send both from client to server and
+ visa versa will be compressed. If server is not supporting any of the suggested algorithms, then it replies with 'n' (no compression)
+ message and it is up to the client whether to continue work without compression or report error.
+ Supported compression algorithms are chosen at configure time. Right now two libraries are supported: zlib (default) and zstd (if Postgres was
+ configured with --with-zstd option). In both cases streaming mode is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="libpq-connect-client-encoding" xreflabel="client_encoding">
<term><literal>client_encoding</literal></term>
<listitem>
diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
index a46cb72..6ff5777 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -92,6 +92,15 @@
such as <command>COPY</command>.
</para>
+ <para>
+ It is possible to compress protocol data to reduce traffic and speed-up client-server interaction.
+ Compression is especial useful for importing/exporting data to/from database using COPY command
+ and for replication (both physical and logical). Also compression can reduce server response time
+ in case of queries returning large amount of data (for example returning JSON, BLOBs, text,...)
+ Right now two libraries are supported: zlib (default) and zstd (if Postgres was
+ configured with --with-zstd option). In both cases streaming mode is used.
+ </para>
+
<sect2 id="protocol-message-concepts">
<title>Messaging Overview</title>
@@ -263,6 +272,21 @@
</varlistentry>
<varlistentry>
+ <term>CompressionAck</term>
+ <listitem>
+ <para>
+ Server acknowledges using compression for client-server communication protocol.
+ Compression can be requested by client by including "compression" option in connection string.
+ Client sends to the server list of compression algorithms, supported by client library
+ (compression algorithm is identified by one letter: <literal>'f'</literal> - Facebook zstd, <literal>'z'</literal> - zlib,...).
+ If server supports one of this algorithms, then it acknowledges use of this algorithm and all subsequent libpq messages send both from client to server and
+ visa versa will be compressed. If server is not supporting any of the suggested algorithms, then it replies with 'n' (no compression)
+ algorithm identifier and it is up to the client whether to continue work without compression or report error.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
<term>AuthenticationOk</term>
<listitem>
<para>
@@ -3396,6 +3420,56 @@ following:
</listitem>
</varlistentry>
+<varlistentry>
+<term>
+CompressionAck (B)
+</term>
+<listitem>
+<para>
+
+<variablelist>
+<varlistentry>
+<term>
+ Byte1('z')
+</term>
+<listitem>
+<para>
+ Acknowledge use of compression for protocol data. Client sends to the server list of compression algorithms, supported by client library.
+ If server supports one of this algorithms, then it responds with CompressionAck with identifier (letter) of first such algorithm.
+ If server is not supporting any of the suggested algorithms, then it replies with 'n' (no compression) algorithm.
+ It is up to the client whether to continue work without compression or report error.
+ After receiving this message with algorithm identifer aother than 'n', both server and client are switched to compression mode
+ and exchange compressed messages.
+</para>
+</listitem>
+</varlistentry>
+<varlistentry>
+<term>
+ Int32
+</term>
+<listitem>
+<para>
+ Length of message contents in bytes, including self.
+</para>
+</listitem>
+</varlistentry>
+<varlistentry>
+<term>
+ Byte1
+</term>
+<listitem>
+<para>
+ Used compression algorithm. Right now the following streaming compression algorithms are supported: 'f' - Facebook zstd, 'z' - zlib, 'n' - no compression.
+</para>
+</listitem>
+</varlistentry>
+</variablelist>
+
+</para>
+</listitem>
+</varlistentry>
+
+
<varlistentry>
<term>
@@ -5961,6 +6035,19 @@ StartupMessage (F)
</para>
</listitem>
</varlistentry>
+<varlistentry>
+<term>
+ <literal>compression</literal>
+</term>
+<listitem>
+<para>
+ Request compression of libpq traffic. Value is list of compression algorithms supported by client:
+ <literal>'f'</literal> - Facebook zstd, <literal>'z'</literal> - zlib, <literal>'n'</literal> - no compression.
+ By default compression is disabled. Please notice that using compression together with SSL may add extra vulnerabilities:
+ <ulink url="https://en.wikipedia.org/wiki/CRIME";>CRIME</ulink>.
+</para>
+</listitem>
+</varlistentry>
</variablelist>
In addition to the above, other parameters may be listed.
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 7ca1e9a..9e11599 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -196,6 +196,7 @@ with_llvm = @with_llvm@
with_system_tzdata = @with_system_tzdata@
with_uuid = @with_uuid@
with_zlib = @with_zlib@
+with_zstd = @with_zstd@
enable_rpath = @enable_rpath@
enable_nls = @enable_nls@
enable_debug = @enable_debug@
diff --git a/src/backend/Makefile b/src/backend/Makefile
index 9706a95..f32a780 100644
--- a/src/backend/Makefile
+++ b/src/backend/Makefile
@@ -54,6 +54,14 @@ ifeq ($(with_systemd),yes)
LIBS += -lsystemd
endif
+ifeq ($(with_zstd),yes)
+LIBS += -lzstd
+endif
+
+ifeq ($(with_zlib),yes)
+LIBS += -lz
+endif
+
##########################################################################
all: submake-libpgport submake-catalog-headers submake-utils-headers postgres $(POSTGRES_IMP)
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index ac986c0..cbf453d 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -93,6 +93,7 @@
#include "storage/ipc.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "common/zpq_stream.h"
/*
* Cope with the various platform-specific ways to spell TCP keepalive socket
@@ -141,6 +142,9 @@ static char PqRecvBuffer[PQ_RECV_BUFFER_SIZE];
static int PqRecvPointer; /* Next index to read a byte from PqRecvBuffer */
static int PqRecvLength; /* End of data available in PqRecvBuffer */
+static ZpqStream* PqStream;
+
+
/*
* Message status
*/
@@ -183,6 +187,56 @@ const PQcommMethods *PqCommMethods = &PqCommSocketMethods;
WaitEventSet *FeBeWaitSet;
+/* --------------------------------
+ * pq_configure - configure connection using port settings
+ *
+ * Right now only compression is toggled in the configure.
+ * Function returns 0 in case of success, non-null in case of error
+ * --------------------------------
+ */
+int
+pq_configure(Port* port)
+{
+ char* client_compression_algorithms = port->compression_algorithms;
+ /*
+ * If client request compression, it sends list of supported compression algorithms.
+ * Each compression algorirthm is idetified by one letter ('f' - Facebook zsts, 'z' - xlib)
+ */
+ if (client_compression_algorithms)
+ {
+ char server_compression_algorithms[ZPQ_MAX_ALGORITHMS];
+ char compression_algorithm = ZPQ_NO_COMPRESSION;
+ char compression[6] = {'z',0,0,0,5,0}; /* message length = 5 */
+ int rc;
+
+ /* Get list of compression algorithms, supported by server */
+ zpq_get_supported_algorithms(server_compression_algorithms);
+
+ /* Intersect lists */
+ while (*client_compression_algorithms != '\0')
+ {
+ if (strchr(server_compression_algorithms, *client_compression_algorithms))
+ {
+ compression_algorithm = *client_compression_algorithms;
+ break;
+ }
+ client_compression_algorithms += 1;
+ }
+
+ compression[5] = compression_algorithm;
+ /* Send 'z' message to the client with selectde comression algorithm ('n' if match is ont found) */
+ socket_set_nonblocking(false);
+ while ((rc = secure_write(MyProcPort, compression, sizeof(compression))) < 0
+ && errno == EINTR);
+ if ((size_t)rc != sizeof(compression))
+ return -1;
+
+ /* initialize compression */
+ if (zpq_set_algorithm(compression_algorithm))
+ PqStream = zpq_create((zpq_tx_func)secure_write, (zpq_rx_func)secure_read, MyProcPort);
+ }
+ return 0;
+}
/* --------------------------------
* pq_init - initialize libpq at backend startup
@@ -280,6 +334,9 @@ socket_close(int code, Datum arg)
free(MyProcPort->gss);
#endif /* ENABLE_GSS || ENABLE_SSPI */
+ /* Release compression streams */
+ zpq_free(PqStream);
+
/*
* Cleanly shut down SSL layer. Nowhere else does a postmaster child
* call this, so this is safe when interrupting BackendInitialize().
@@ -919,12 +976,15 @@ socket_set_nonblocking(bool nonblocking)
/* --------------------------------
* pq_recvbuf - load some bytes into the input buffer
*
- * returns 0 if OK, EOF if trouble
+ * nowait parameter toggles non-blocking mode.
+ * returns number of read bytes, EOF if trouble
* --------------------------------
*/
static int
-pq_recvbuf(void)
+pq_recvbuf(bool nowait)
{
+ int r;
+
if (PqRecvPointer > 0)
{
if (PqRecvLength > PqRecvPointer)
@@ -940,21 +1000,38 @@ pq_recvbuf(void)
}
/* Ensure that we're in blocking mode */
- socket_set_nonblocking(false);
+ socket_set_nonblocking(nowait);
/* Can fill buffer from PqRecvLength and upwards */
for (;;)
{
- int r;
-
- r = secure_read(MyProcPort, PqRecvBuffer + PqRecvLength,
- PQ_RECV_BUFFER_SIZE - PqRecvLength);
+ size_t processed = 0;
+ /* If srteaming compression is enabled then use correpondent comression read function. */
+ r = PqStream
+ ? zpq_read(PqStream, PqRecvBuffer + PqRecvLength,
+ PQ_RECV_BUFFER_SIZE - PqRecvLength, &processed)
+ : secure_read(MyProcPort, PqRecvBuffer + PqRecvLength,
+ PQ_RECV_BUFFER_SIZE - PqRecvLength);
+ PqRecvLength += processed;
if (r < 0)
{
+ if (r == ZPQ_DECOMPRESS_ERROR)
+ {
+ char const* msg = zpq_error(PqStream);
+ if (msg == NULL)
+ msg = "end of stream";
+ ereport(COMMERROR,
+ (errcode_for_socket_access(),
+ errmsg("failed to decompress data: %s", msg)));
+ return EOF;
+ }
if (errno == EINTR)
continue; /* Ok if interrupted */
+ if (nowait && (errno == EAGAIN || errno == EWOULDBLOCK))
+ return 0;
+
/*
* Careful: an ereport() that tries to write to the client would
* cause recursion to here, leading to stack overflow and core
@@ -975,7 +1052,7 @@ pq_recvbuf(void)
}
/* r contains number of bytes read, so just incr length */
PqRecvLength += r;
- return 0;
+ return r;
}
}
@@ -990,7 +1067,7 @@ pq_getbyte(void)
while (PqRecvPointer >= PqRecvLength)
{
- if (pq_recvbuf()) /* If nothing in buffer, then recv some */
+ if (pq_recvbuf(false) == EOF) /* If nothing in buffer, then recv some */
return EOF; /* Failed to recv data */
}
return (unsigned char) PqRecvBuffer[PqRecvPointer++];
@@ -1009,7 +1086,7 @@ pq_peekbyte(void)
while (PqRecvPointer >= PqRecvLength)
{
- if (pq_recvbuf()) /* If nothing in buffer, then recv some */
+ if (pq_recvbuf(false) == EOF) /* If nothing in buffer, then recv some */
return EOF; /* Failed to recv data */
}
return (unsigned char) PqRecvBuffer[PqRecvPointer];
@@ -1030,44 +1107,11 @@ pq_getbyte_if_available(unsigned char *c)
Assert(PqCommReadingMsg);
- if (PqRecvPointer < PqRecvLength)
+ if (PqRecvPointer < PqRecvLength || (r = pq_recvbuf(true)) > 0)
{
*c = PqRecvBuffer[PqRecvPointer++];
return 1;
}
-
- /* Put the socket into non-blocking mode */
- socket_set_nonblocking(true);
-
- r = secure_read(MyProcPort, c, 1);
- if (r < 0)
- {
- /*
- * Ok if no data available without blocking or interrupted (though
- * EINTR really shouldn't happen with a non-blocking socket). Report
- * other errors.
- */
- if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
- r = 0;
- else
- {
- /*
- * Careful: an ereport() that tries to write to the client would
- * cause recursion to here, leading to stack overflow and core
- * dump! This message must go *only* to the postmaster log.
- */
- ereport(COMMERROR,
- (errcode_for_socket_access(),
- errmsg("could not receive data from client: %m")));
- r = EOF;
- }
- }
- else if (r == 0)
- {
- /* EOF detected */
- r = EOF;
- }
-
return r;
}
@@ -1088,7 +1132,7 @@ pq_getbytes(char *s, size_t len)
{
while (PqRecvPointer >= PqRecvLength)
{
- if (pq_recvbuf()) /* If nothing in buffer, then recv some */
+ if (pq_recvbuf(false) == EOF) /* If nothing in buffer, then recv some */
return EOF; /* Failed to recv data */
}
amount = PqRecvLength - PqRecvPointer;
@@ -1122,7 +1166,7 @@ pq_discardbytes(size_t len)
{
while (PqRecvPointer >= PqRecvLength)
{
- if (pq_recvbuf()) /* If nothing in buffer, then recv some */
+ if (pq_recvbuf(false) == EOF) /* If nothing in buffer, then recv some */
return EOF; /* Failed to recv data */
}
amount = PqRecvLength - PqRecvPointer;
@@ -1163,7 +1207,7 @@ pq_getstring(StringInfo s)
{
while (PqRecvPointer >= PqRecvLength)
{
- if (pq_recvbuf()) /* If nothing in buffer, then recv some */
+ if (pq_recvbuf(false) == EOF) /* If nothing in buffer, then recv some */
return EOF; /* Failed to recv data */
}
@@ -1413,13 +1457,18 @@ internal_flush(void)
char *bufptr = PqSendBuffer + PqSendStart;
char *bufend = PqSendBuffer + PqSendPointer;
- while (bufptr < bufend)
+ while (bufptr < bufend || zpq_buffered(PqStream) != 0) /* has more data to flush or unsent data in internal compression buffer */
{
- int r;
-
- r = secure_write(MyProcPort, bufptr, bufend - bufptr);
-
- if (r <= 0)
+ int r;
+ size_t processed = 0;
+ size_t available = bufend - bufptr;
+ r = PqStream
+ ? zpq_write(PqStream, bufptr, available, &processed)
+ : secure_write(MyProcPort, bufptr, available);
+ bufptr += processed;
+ PqSendStart += processed;
+
+ if (r < 0 || (r == 0 && available))
{
if (errno == EINTR)
continue; /* Ok if we were interrupted */
@@ -1467,7 +1516,6 @@ internal_flush(void)
bufptr += r;
PqSendStart += r;
}
-
PqSendStart = PqSendPointer = 0;
return 0;
}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 959e3b8..60ff1e7 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -2151,6 +2151,8 @@ retry1:
port->database_name = pstrdup(valptr);
else if (strcmp(nameptr, "user") == 0)
port->user_name = pstrdup(valptr);
+ else if (strcmp(nameptr, "compression") == 0)
+ port->compression_algorithms = pstrdup(valptr);
else if (strcmp(nameptr, "options") == 0)
port->cmdline_options = pstrdup(valptr);
else if (strcmp(nameptr, "replication") == 0)
@@ -4458,6 +4460,14 @@ BackendInitialize(Port *port)
if (status != STATUS_OK)
proc_exit(0);
+ if (pq_configure(port))
+ {
+ ereport(COMMERROR,
+ (errcode_for_socket_access(),
+ errmsg("failed to send compression message: %m")));
+ proc_exit(0);
+ }
+
/*
* Now that we have the user and database name, we can set the process
* title for ps. It's good to do this as early as possible in startup.
diff --git a/src/common/Makefile b/src/common/Makefile
index 25c55bd..bc6cba8 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -77,7 +77,8 @@ OBJS_COMMON = \
unicode_norm.o \
username.o \
wait_error.o \
- wchar.o
+ wchar.o \
+ zpq_stream.o
ifeq ($(with_openssl),yes)
OBJS_COMMON += \
diff --git a/src/common/zpq_stream.c b/src/common/zpq_stream.c
new file mode 100644
index 0000000..3fc9e27
--- /dev/null
+++ b/src/common/zpq_stream.c
@@ -0,0 +1,500 @@
+#include "postgres_fe.h"
+#include "common/zpq_stream.h"
+#include "c.h"
+#include "pg_config.h"
+
+/*
+ * Functions implementing streaming compression algorithm
+ */
+typedef struct
+{
+ /*
+ * Returns letter identifying compression algorithm.
+ */
+ char (*name)(void);
+
+ /*
+ * Create compression stream with using rx/tx function for fetching/sending compressed data
+ */
+ ZpqStream* (*create)(zpq_tx_func tx_func, zpq_rx_func rx_func, void *arg);
+
+ /*
+ * Read up to "size" raw (decompressed) bytes.
+ * Returns number of decompressed bytes or error code. In the last case amount of decompressed bytes is stored in *processed.
+ * Error code is either ZPQ_DECOMPRESS_ERROR either error code returned by the rx function.
+ */
+ ssize_t (*read)(ZpqStream *zs, void *buf, size_t size, size_t *processed);
+
+ /*
+ * Write up to "size" raw (decompressed) bytes.
+ * Returns number of written raw bytes or error code returned by tx function.
+ * In the last case amount of written raw bytes is stored in *processed.
+ */
+ ssize_t (*write)(ZpqStream *zs, void const *buf, size_t size, size_t *processed);
+
+ /*
+ * Free stream created by create function.
+ */
+ void (*free)(ZpqStream *zs);
+
+ /*
+ * Get error message.
+ */
+ char const* (*error)(ZpqStream *zs);
+
+ /*
+ * Returns amount of data in internal compression buffer.
+ */
+ size_t (*buffered)(ZpqStream *zs);
+} ZpqAlgorithm;
+
+
+#if HAVE_LIBZSTD
+
+#include <stdlib.h>
+#include <zstd.h>
+
+#define ZSTD_BUFFER_SIZE (8*1024)
+#define ZSTD_COMPRESSION_LEVEL 1
+
+typedef struct ZstdStream
+{
+ ZSTD_CStream* tx_stream;
+ ZSTD_DStream* rx_stream;
+ ZSTD_outBuffer tx;
+ ZSTD_inBuffer rx;
+ size_t tx_not_flushed; /* Amount of data in internal zstd buffer */
+ size_t tx_buffered; /* Data which is consumed by ztd_read but not yet sent */
+ zpq_tx_func tx_func;
+ zpq_rx_func rx_func;
+ void* arg;
+ char const* rx_error; /* Decompress error message */
+ size_t tx_total;
+ size_t tx_total_raw;
+ size_t rx_total;
+ size_t rx_total_raw;
+ char tx_buf[ZSTD_BUFFER_SIZE];
+ char rx_buf[ZSTD_BUFFER_SIZE];
+} ZstdStream;
+
+static ZpqStream*
+zstd_create(zpq_tx_func tx_func, zpq_rx_func rx_func, void *arg)
+{
+ ZstdStream* zs = (ZstdStream*)malloc(sizeof(ZstdStream));
+ zs->tx_stream = ZSTD_createCStream();
+ ZSTD_initCStream(zs->tx_stream, ZSTD_COMPRESSION_LEVEL);
+ zs->rx_stream = ZSTD_createDStream();
+ ZSTD_initDStream(zs->rx_stream);
+ zs->tx.dst = zs->tx_buf;
+ zs->tx.pos = 0;
+ zs->tx.size = ZSTD_BUFFER_SIZE;
+ zs->rx.src = zs->rx_buf;
+ zs->rx.pos = 0;
+ zs->rx.size = 0;
+ zs->rx_func = rx_func;
+ zs->tx_func = tx_func;
+ zs->tx_buffered = 0;
+ zs->tx_not_flushed = 0;
+ zs->rx_error = NULL;
+ zs->arg = arg;
+ zs->tx_total = zs->tx_total_raw = 0;
+ zs->rx_total = zs->rx_total_raw = 0;
+ return (ZpqStream*)zs;
+}
+
+static ssize_t
+zstd_read(ZpqStream *zstream, void *buf, size_t size, size_t *processed)
+{
+ ZstdStream* zs = (ZstdStream*)zstream;
+ ssize_t rc;
+ ZSTD_outBuffer out;
+ out.dst = buf;
+ out.pos = 0;
+ out.size = size;
+
+ while (1)
+ {
+ rc = ZSTD_decompressStream(zs->rx_stream, &out, &zs->rx);
+ if (ZSTD_isError(rc))
+ {
+ zs->rx_error = ZSTD_getErrorName(rc);
+ return ZPQ_DECOMPRESS_ERROR;
+ }
+ /* Return result if we fill requested amount of bytes or read operation was performed */
+ if (out.pos != 0)
+ {
+ zs->rx_total_raw += out.pos;
+ return out.pos;
+ }
+ if (zs->rx.pos == zs->rx.size)
+ {
+ zs->rx.pos = zs->rx.size = 0; /* Reset rx buffer */
+ }
+ rc = zs->rx_func(zs->arg, (char*)zs->rx.src + zs->rx.size, ZSTD_BUFFER_SIZE - zs->rx.size);
+ if (rc > 0) /* read fetches some data */
+ {
+ zs->rx.size += rc;
+ zs->rx_total += rc;
+ }
+ else /* read failed */
+ {
+ *processed = out.pos;
+ zs->rx_total_raw += out.pos;
+ return rc;
+ }
+ }
+}
+
+static ssize_t
+zstd_write(ZpqStream *zstream, void const *buf, size_t size, size_t *processed)
+{
+ ZstdStream* zs = (ZstdStream*)zstream;
+ ssize_t rc;
+ ZSTD_inBuffer in_buf;
+ in_buf.src = buf;
+ in_buf.pos = 0;
+ in_buf.size = size;
+
+ do
+ {
+ if (zs->tx.pos == 0) /* Compress buffer is empty */
+ {
+ zs->tx.dst = zs->tx_buf; /* Reset pointer to the beginning of buffer */
+
+ if (in_buf.pos < size) /* Has something to compress in input buffer */
+ ZSTD_compressStream(zs->tx_stream, &zs->tx, &in_buf);
+
+ if (in_buf.pos == size) /* All data is compressed: flushed internal zstd buffer */
+ {
+ zs->tx_not_flushed = ZSTD_flushStream(zs->tx_stream, &zs->tx);
+ }
+ }
+ rc = zs->tx_func(zs->arg, zs->tx.dst, zs->tx.pos);
+ if (rc > 0)
+ {
+ zs->tx.pos -= rc;
+ zs->tx.dst = (char*)zs->tx.dst + rc;
+ zs->tx_total += rc;
+ }
+ else
+ {
+ *processed = in_buf.pos;
+ zs->tx_buffered = zs->tx.pos;
+ zs->tx_total_raw += in_buf.pos;
+ return rc;
+ }
+ } while (zs->tx.pos == 0 && (in_buf.pos < size || zs->tx_not_flushed)); /* repeat sending data until first partial write */
+
+ zs->tx_total_raw += in_buf.pos;
+ zs->tx_buffered = zs->tx.pos;
+ return in_buf.pos;
+}
+
+static void
+zstd_free(ZpqStream *zstream)
+{
+ ZstdStream* zs = (ZstdStream*)zstream;
+ if (zs != NULL)
+ {
+ ZSTD_freeCStream(zs->tx_stream);
+ ZSTD_freeDStream(zs->rx_stream);
+ free(zs);
+ }
+}
+
+static char const*
+zstd_error(ZpqStream *zstream)
+{
+ ZstdStream* zs = (ZstdStream*)zstream;
+ return zs->rx_error;
+}
+
+static size_t
+zstd_buffered(ZpqStream *zstream)
+{
+ ZstdStream* zs = (ZstdStream*)zstream;
+ return zs != NULL ? zs->tx_buffered + zs->tx_not_flushed : 0;
+}
+
+static char
+zstd_name(void)
+{
+ return 'f';
+}
+
+#endif
+
+#if HAVE_LIBZ
+
+#include <stdlib.h>
+#include <zlib.h>
+
+#define ZLIB_BUFFER_SIZE 8192
+#define ZLIB_COMPRESSION_LEVEL 1
+
+typedef struct ZlibStream
+{
+ z_stream tx;
+ z_stream rx;
+
+ zpq_tx_func tx_func;
+ zpq_rx_func rx_func;
+ void* arg;
+
+ size_t tx_buffered;
+
+ Bytef tx_buf[ZLIB_BUFFER_SIZE];
+ Bytef rx_buf[ZLIB_BUFFER_SIZE];
+} ZlibStream;
+
+static ZpqStream*
+zlib_create(zpq_tx_func tx_func, zpq_rx_func rx_func, void *arg)
+{
+ int rc;
+ ZlibStream* zs = (ZlibStream*)malloc(sizeof(ZlibStream));
+ memset(&zs->tx, 0, sizeof(zs->tx));
+ zs->tx.next_out = zs->tx_buf;
+ zs->tx.avail_out = ZLIB_BUFFER_SIZE;
+ zs->tx_buffered = 0;
+ rc = deflateInit(&zs->tx, ZLIB_COMPRESSION_LEVEL);
+ if (rc != Z_OK)
+ {
+ free(zs);
+ return NULL;
+ }
+ Assert(zs->tx.next_out == zs->tx_buf && zs->tx.avail_out == ZLIB_BUFFER_SIZE);
+
+ memset(&zs->rx, 0, sizeof(zs->tx));
+ zs->rx.next_in = zs->rx_buf;
+ zs->rx.avail_in = ZLIB_BUFFER_SIZE;
+ rc = inflateInit(&zs->rx);
+ if (rc != Z_OK)
+ {
+ free(zs);
+ return NULL;
+ }
+ Assert(zs->rx.next_in == zs->rx_buf && zs->rx.avail_in == ZLIB_BUFFER_SIZE);
+ zs->rx.avail_in = 0;
+
+ zs->rx_func = rx_func;
+ zs->tx_func = tx_func;
+ zs->arg = arg;
+
+ return (ZpqStream*)zs;
+}
+
+static ssize_t
+zlib_read(ZpqStream *zstream, void *buf, size_t size, size_t *processed)
+{
+ ZlibStream* zs = (ZlibStream*)zstream;
+ int rc;
+ zs->rx.next_out = (Bytef *)buf;
+ zs->rx.avail_out = size;
+
+ while (1)
+ {
+ if (zs->rx.avail_in != 0) /* If there is some data in receiver buffer, then decompress it */
+ {
+ rc = inflate(&zs->rx, Z_SYNC_FLUSH);
+ if (rc != Z_OK && rc != Z_BUF_ERROR)
+ {
+ return ZPQ_DECOMPRESS_ERROR;
+ }
+ if (zs->rx.avail_out != size)
+ {
+ return size - zs->rx.avail_out;
+ }
+ if (zs->rx.avail_in == 0)
+ {
+ zs->rx.next_in = zs->rx_buf;
+ }
+ }
+ else
+ {
+ zs->rx.next_in = zs->rx_buf;
+ }
+ rc = zs->rx_func(zs->arg, zs->rx.next_in + zs->rx.avail_in, zs->rx_buf + ZLIB_BUFFER_SIZE - zs->rx.next_in - zs->rx.avail_in);
+ if (rc > 0)
+ {
+ zs->rx.avail_in += rc;
+ }
+ else
+ {
+ *processed = size - zs->rx.avail_out;
+ return rc;
+ }
+ }
+}
+
+static ssize_t
+zlib_write(ZpqStream *zstream, void const *buf, size_t size, size_t *processed)
+{
+ ZlibStream* zs = (ZlibStream*)zstream;
+ int rc;
+ zs->tx.next_in = (Bytef *)buf;
+ zs->tx.avail_in = size;
+ do
+ {
+ if (zs->tx.avail_out == ZLIB_BUFFER_SIZE) /* Compress buffer is empty */
+ {
+ zs->tx.next_out = zs->tx_buf; /* Reset pointer to the beginning of buffer */
+
+ if (zs->tx.avail_in != 0) /* Has something in input buffer */
+ {
+ rc = deflate(&zs->tx, Z_SYNC_FLUSH);
+ Assert(rc == Z_OK);
+ zs->tx.next_out = zs->tx_buf; /* Reset pointer to the beginning of buffer */
+ }
+ }
+ rc = zs->tx_func(zs->arg, zs->tx.next_out, ZLIB_BUFFER_SIZE - zs->tx.avail_out);
+ if (rc > 0)
+ {
+ zs->tx.next_out += rc;
+ zs->tx.avail_out += rc;
+ }
+ else
+ {
+ *processed = size - zs->tx.avail_in;
+ zs->tx_buffered = ZLIB_BUFFER_SIZE - zs->tx.avail_out;
+ return rc;
+ }
+ } while (zs->tx.avail_out == ZLIB_BUFFER_SIZE && zs->tx.avail_in != 0); /* repeat sending data until first partial write */
+
+ zs->tx_buffered = ZLIB_BUFFER_SIZE - zs->tx.avail_out;
+
+ return size - zs->tx.avail_in;
+}
+
+static void
+zlib_free(ZpqStream *zstream)
+{
+ ZlibStream* zs = (ZlibStream*)zstream;
+ if (zs != NULL)
+ {
+ inflateEnd(&zs->rx);
+ deflateEnd(&zs->tx);
+ free(zs);
+ }
+}
+
+static char const*
+zlib_error(ZpqStream *zstream)
+{
+ ZlibStream* zs = (ZlibStream*)zstream;
+ return zs->rx.msg;
+}
+
+static size_t
+zlib_buffered(ZpqStream *zstream)
+{
+ ZlibStream* zs = (ZlibStream*)zstream;
+ return zs != NULL ? zs->tx_buffered : 0;
+}
+
+static char
+zlib_name(void)
+{
+ return 'z';
+}
+
+#endif
+
+/*
+ * Array with all supported compression algorithms.
+ */
+static ZpqAlgorithm const zpq_algorithms[] =
+{
+#if HAVE_LIBZSTD
+ {zstd_name, zstd_create, zstd_read, zstd_write, zstd_free, zstd_error, zstd_buffered},
+#endif
+#if HAVE_LIBZ
+ {zlib_name, zlib_create, zlib_read, zlib_write, zlib_free, zlib_error, zlib_buffered},
+#endif
+ {NULL}
+};
+
+/*
+ * Index of used compression algorithm in zpq_algorithms array.
+ */
+static int zpq_algorithm_impl;
+
+
+ZpqStream*
+zpq_create(zpq_tx_func tx_func, zpq_rx_func rx_func, void *arg)
+{
+ return zpq_algorithms[zpq_algorithm_impl].create(tx_func, rx_func, arg);
+}
+
+ssize_t
+zpq_read(ZpqStream *zs, void *buf, size_t size, size_t* processed)
+{
+ return zpq_algorithms[zpq_algorithm_impl].read(zs, buf, size, processed);
+}
+
+ssize_t
+zpq_write(ZpqStream *zs, void const *buf, size_t size, size_t* processed)
+{
+ return zpq_algorithms[zpq_algorithm_impl].write(zs, buf, size, processed);
+}
+
+void
+zpq_free(ZpqStream *zs)
+{
+ if (zs)
+ zpq_algorithms[zpq_algorithm_impl].free(zs);
+}
+
+char const*
+zpq_error(ZpqStream *zs)
+{
+ return zpq_algorithms[zpq_algorithm_impl].error(zs);
+}
+
+
+size_t
+zpq_buffered(ZpqStream *zs)
+{
+ return zs ? zpq_algorithms[zpq_algorithm_impl].buffered(zs) : 0;
+}
+
+/*
+ * Get list of the supported algorithms.
+ * Each algorithm is identified by one letter: 'f' - Facebook zstd, 'z' - zlib.
+ * Algorithm identifies are appended to the provided buffer and terminated by '\0'.
+ */
+void
+zpq_get_supported_algorithms(char algorithms[ZPQ_MAX_ALGORITHMS])
+{
+ int i;
+ for (i = 0; zpq_algorithms[i].name != NULL; i++)
+ {
+ Assert(i < ZPQ_MAX_ALGORITHMS);
+ algorithms[i] = zpq_algorithms[i].name();
+ }
+ Assert(i < ZPQ_MAX_ALGORITHMS);
+ algorithms[i] = '\0';
+}
+
+/*
+ * Choose current algorithm implementation.
+ * Returns true if algorithm identifier is located in the list of the supported algorithms,
+ * false otherwise
+ */
+bool
+zpq_set_algorithm(char name)
+{
+ int i;
+ if (name != ZPQ_NO_COMPRESSION)
+ {
+ for (i = 0; zpq_algorithms[i].name != NULL; i++)
+ {
+ if (zpq_algorithms[i].name() == name)
+ {
+ zpq_algorithm_impl = i;
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
diff --git a/src/include/common/zpq_stream.h b/src/include/common/zpq_stream.h
new file mode 100644
index 0000000..6f2aec1
--- /dev/null
+++ b/src/include/common/zpq_stream.h
@@ -0,0 +1,32 @@
+/*
+ * zpq_stream.h
+ * Streaiming compression for libpq
+ */
+
+#ifndef ZPQ_STREAM_H
+#define ZPQ_STREAM_H
+
+#include <stdlib.h>
+
+#define ZPQ_IO_ERROR (-1)
+#define ZPQ_DECOMPRESS_ERROR (-2)
+#define ZPQ_MAX_ALGORITHMS (8)
+#define ZPQ_NO_COMPRESSION 'n'
+
+struct ZpqStream;
+typedef struct ZpqStream ZpqStream;
+
+typedef ssize_t(*zpq_tx_func)(void* arg, void const* data, size_t size);
+typedef ssize_t(*zpq_rx_func)(void* arg, void* data, size_t size);
+
+ZpqStream* zpq_create(zpq_tx_func tx_func, zpq_rx_func rx_func, void* arg);
+ssize_t zpq_read(ZpqStream* zs, void* buf, size_t size, size_t* processed);
+ssize_t zpq_write(ZpqStream* zs, void const* buf, size_t size, size_t* processed);
+char const* zpq_error(ZpqStream* zs);
+size_t zpq_buffered(ZpqStream* zs);
+void zpq_free(ZpqStream* zs);
+
+void zpq_get_supported_algorithms(char algorithms[ZPQ_MAX_ALGORITHMS]);
+bool zpq_set_algorithm(char name);
+
+#endif
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 0a23281..5289f9f 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -170,6 +170,8 @@ typedef struct Port
int keepalives_count;
int tcp_user_timeout;
+ char* compression_algorithms; /* Compression algorithms supported by client */
+
/*
* GSSAPI structures.
*/
diff --git a/src/include/libpq/libpq.h b/src/include/libpq/libpq.h
index b115247..224ff3d 100644
--- a/src/include/libpq/libpq.h
+++ b/src/include/libpq/libpq.h
@@ -63,6 +63,7 @@ extern void StreamClose(pgsocket sock);
extern void TouchSocketFiles(void);
extern void RemoveSocketFiles(void);
extern void pq_init(void);
+extern int pq_configure(Port* port);
extern int pq_getbytes(char *s, size_t len);
extern int pq_getstring(StringInfo s);
extern void pq_startmsgread(void);
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index fb270df..b829fed 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -349,6 +349,9 @@
/* Define to 1 if you have the `link' function. */
#undef HAVE_LINK
+/* Define to 1 if you have the `zstd' library (-lzstd). */
+#undef HAVE_LIBZSTD
+
/* Define to 1 if the system has the type `locale_t'. */
#undef HAVE_LOCALE_T
diff --git a/src/interfaces/libpq/Makefile b/src/interfaces/libpq/Makefile
index 4ac5f4b..be8cb34 100644
--- a/src/interfaces/libpq/Makefile
+++ b/src/interfaces/libpq/Makefile
@@ -29,6 +29,20 @@ endif
# The MSVC build system scrapes OBJS from this file. If you change any of
# the conditional additions of files to OBJS, update Mkvcbuild.pm to match.
+ifeq ($(with_zstd),yes)
+LIBS += -lzstd
+SHLIB_LINK += -lzstd
+endif
+
+ifeq ($(with_zlib),yes)
+LIBS += -lz
+SHLIB_LINK += -lz
+endif
+
+# We can't use Makefile variables here because the MSVC build system scrapes
+# OBJS from this file.
+
+
OBJS = \
$(WIN32RES) \
fe-auth-scram.o \
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index b0ca37c..525341f 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -24,6 +24,7 @@
#include "common/ip.h"
#include "common/link-canary.h"
#include "common/scram-common.h"
+#include "common/zpq_stream.h"
#include "common/string.h"
#include "fe-auth.h"
#include "libpq-fe.h"
@@ -350,6 +351,10 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
"Replication", "D", 5,
offsetof(struct pg_conn, replication)},
+ {"compression", "COMPRESSION", NULL, NULL,
+ "Libpq-compression", "", 1,
+ offsetof(struct pg_conn, compression)},
+
{"target_session_attrs", "PGTARGETSESSIONATTRS",
DefaultTargetSessionAttrs, NULL,
"Target-Session-Attrs", "", 11, /* sizeof("read-write") = 11 */
@@ -458,6 +463,10 @@ pgthreadlock_t pg_g_threadlock = default_threadlock;
void
pqDropConnection(PGconn *conn, bool flushInput)
{
+ /* Release compression streams */
+ zpq_free(conn->zstream);
+ conn->zstream = NULL;
+
/* Drop any SSL state */
pqsecure_close(conn);
@@ -3216,11 +3225,46 @@ keep_going: /* We will come back to here until there is
*/
conn->inCursor = conn->inStart;
- /* Read type byte */
- if (pqGetc(&beresp, conn))
+ while (1)
{
- /* We'll come back when there is more data */
- return PGRES_POLLING_READING;
+ /* Read type byte */
+ if (pqGetc(&beresp, conn))
+ {
+ /* We'll come back when there is more data */
+ return PGRES_POLLING_READING;
+ }
+
+ if (beresp == 'z') /* Switch on compression */
+ {
+ char algorithm;
+ /* Read message length word */
+ if (pqGetInt(&msgLength, 4, conn))
+ {
+ /* We'll come back when there is more data */
+ return PGRES_POLLING_READING;
+ }
+ if (msgLength != 5)
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext(
+ "expected compression algorithm specification message length is 5 bytes, but %d is recevied\n"),
+ msgLength);
+ goto error_return;
+ }
+ pqGetc(&algorithm, conn);
+ if (!zpq_set_algorithm(algorithm))
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext(
+ "server is not supported requested compression algorithm\n"));
+ goto error_return;
+ }
+ /* mark byte consumed */
+ conn->inStart = conn->inCursor;
+ Assert(!conn->zstream);
+ conn->zstream = zpq_create((zpq_tx_func)pqsecure_write, (zpq_rx_func)pqsecure_read, conn);
+ } else
+ break;
}
/*
@@ -4020,6 +4064,8 @@ freePGconn(PGconn *conn)
free(conn->dbName);
if (conn->replication)
free(conn->replication);
+ if (conn->compression)
+ free(conn->compression);
if (conn->pguser)
free(conn->pguser);
if (conn->pgpass)
diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index 4ffc7f3..e57f401 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -53,12 +53,21 @@
#include "pg_config_paths.h"
#include "port/pg_bswap.h"
+#include <common/zpq_stream.h>
+
static int pqPutMsgBytes(const void *buf, size_t len, PGconn *conn);
static int pqSendSome(PGconn *conn, int len);
static int pqSocketCheck(PGconn *conn, int forRead, int forWrite,
time_t end_time);
static int pqSocketPoll(int sock, int forRead, int forWrite, time_t end_time);
+#define pq_read_conn(conn,processed) \
+ (conn->zstream \
+ ? zpq_read(conn->zstream, conn->inBuffer + conn->inEnd, \
+ conn->inBufSize - conn->inEnd, &processed) \
+ : pqsecure_read(conn, conn->inBuffer + conn->inEnd, \
+ conn->inBufSize - conn->inEnd))
+
/*
* PQlibVersion: return the libpq version number
*/
@@ -616,6 +625,7 @@ pqReadData(PGconn *conn)
{
int someread = 0;
int nread;
+ size_t processed;
if (conn->sock == PGINVALID_SOCKET)
{
@@ -664,10 +674,19 @@ pqReadData(PGconn *conn)
/* OK, try to read some data */
retry3:
- nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
- conn->inBufSize - conn->inEnd);
+ processed = 0;
+ nread = pq_read_conn(conn,processed);
+ conn->inEnd += processed;
if (nread < 0)
{
+ if (nread == ZPQ_DECOMPRESS_ERROR)
+ {
+ printfPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("decompress error: %s\n"),
+ zpq_error(conn->zstream));
+ return -1;
+ }
+
switch (SOCK_ERRNO)
{
case EINTR:
@@ -759,10 +778,20 @@ retry3:
* arrived.
*/
retry4:
- nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
- conn->inBufSize - conn->inEnd);
+ processed = 0;
+ nread = pq_read_conn(conn,processed);
+ conn->inEnd += processed;
+
if (nread < 0)
{
+ if (nread == ZPQ_DECOMPRESS_ERROR)
+ {
+ printfPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("decompress error: %s\n"),
+ zpq_error(conn->zstream));
+ return -1;
+ }
+
switch (SOCK_ERRNO)
{
case EINTR:
@@ -875,12 +904,14 @@ pqSendSome(PGconn *conn, int len)
}
/* while there's still data to send */
- while (len > 0)
+ while (len > 0 || zpq_buffered(conn->zstream))
{
int sent;
-
+ size_t processed = 0;
+ sent = conn->zstream
+ ? zpq_write(conn->zstream, ptr, len, &processed)
#ifndef WIN32
- sent = pqsecure_write(conn, ptr, len);
+ : pqsecure_write(conn, ptr, len);
#else
/*
@@ -888,8 +919,11 @@ pqSendSome(PGconn *conn, int len)
* failure-point appears to be different in different versions of
* Windows, but 64k should always be safe.
*/
- sent = pqsecure_write(conn, ptr, Min(len, 65536));
+ : pqsecure_write(conn, ptr, Min(len, 65536));
#endif
+ ptr += processed;
+ len -= processed;
+ remaining -= processed;
if (sent < 0)
{
@@ -943,7 +977,7 @@ pqSendSome(PGconn *conn, int len)
remaining -= sent;
}
- if (len > 0)
+ if (len > 0 || sent < 0 || zpq_buffered(conn->zstream))
{
/*
* We didn't send it all, wait till we can send more.
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 1696525..ef61348 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -2135,6 +2135,83 @@ pqBuildStartupPacket3(PGconn *conn, int *packetlen,
}
/*
+ * Parse boolean value. This code is copied from backend/utils/atd/bool.c
+ * because it is not available at frontend.
+ */
+static bool
+parse_bool(const char *value, bool *result)
+{
+ switch (*value)
+ {
+ case 't':
+ case 'T':
+ if (pg_strcasecmp(value, "true") == 0)
+ {
+ *result = true;
+ return true;
+ }
+ break;
+ case 'f':
+ case 'F':
+ if (pg_strcasecmp(value, "false") == 0)
+ {
+ *result = false;
+ return true;
+ }
+ break;
+ case 'y':
+ case 'Y':
+ if (pg_strcasecmp(value, "yes") == 0)
+ {
+ *result = true;
+ return true;
+ }
+ break;
+ case 'n':
+ case 'N':
+ if (pg_strcasecmp(value, "no") == 0)
+ {
+ *result = false;
+ return true;
+ }
+ break;
+ case 'o':
+ case 'O':
+ /* 'o' is not unique enough */
+ if (pg_strcasecmp(value, "on") == 0)
+ {
+ *result = true;
+ return true;
+ }
+ else if (pg_strcasecmp(value, "off") == 0)
+ {
+ *result = false;
+ return true;
+ }
+ break;
+ case '1':
+ if (value[1] == '\0')
+ {
+ *result = true;
+ return true;
+ }
+ break;
+ case '0':
+ if (value[1] == '\0')
+ {
+ *result = false;
+ return true;
+ }
+ break;
+ default:
+ break;
+ }
+
+ *result = false; /* suppress compiler warning */
+ return false;
+}
+
+/*
* Build a startup packet given a filled-in PGconn structure.
*
* We need to figure out how much space is needed, then fill it in.
@@ -2180,6 +2257,20 @@ build_startup_packet(const PGconn *conn, char *packet,
ADD_STARTUP_OPTION("replication", conn->replication);
if (conn->pgoptions && conn->pgoptions[0])
ADD_STARTUP_OPTION("options", conn->pgoptions);
+ if (conn->compression && conn->compression[0])
+ {
+ bool enabled;
+ /*
+ * If compressoin is enabled, then send to the server list of compression algorithms
+ * supported by client
+ */
+ if (parse_bool(conn->compression, &enabled))
+ {
+ char compression_algorithms[ZPQ_MAX_ALGORITHMS];
+ zpq_get_supported_algorithms(compression_algorithms);
+ ADD_STARTUP_OPTION("compression", compression_algorithms);
+ }
+ }
if (conn->send_appname)
{
/* Use appname if present, otherwise use fallback */
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 1de91ae..69ad1e9 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -40,6 +40,7 @@
/* include stuff common to fe and be */
#include "getaddrinfo.h"
#include "libpq/pqcomm.h"
+#include "common/zpq_stream.h"
/* include stuff found in fe only */
#include "pqexpbuffer.h"
@@ -369,6 +370,7 @@ struct pg_conn
* "sspi") */
char *ssl_min_protocol_version; /* minimum TLS protocol version */
char *ssl_max_protocol_version; /* maximum TLS protocol version */
+ char *compression; /* stream compression (0 or 1) */
/* Type of connection to make. Possible values: any, read-write. */
char *target_session_attrs;
@@ -527,6 +529,9 @@ struct pg_conn
/* Buffer for receiving various parts of messages */
PQExpBufferData workBuffer; /* expansible string */
+
+ /* Compression stream */
+ ZpqStream* zstream;
};
/* PGcancel stores all data necessary to cancel a connection. A copy of this
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 90594bd..daac58c 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -123,7 +123,7 @@ sub mkvcbuild
config_info.c controldata_utils.c d2s.c encnames.c exec.c
f2s.c file_perm.c file_utils.c hashfn.c ip.c jsonapi.c
keywords.c kwlookup.c link-canary.c md5.c
- pg_get_line.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
+ pg_get_line.c zpq_stream.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
saslprep.c scram-common.c string.c stringinfo.c unicode_norm.c username.c
wait_error.c wchar.c);
