Merge the changes for #188 and #191 which add an intermediate pipe on the input side to allow splice() to be used for all transfers.

docs/pv.1

@@ -291,6 +291,14 @@ automatically switches on \*(lq\fB\-\-no\-splice\fR\*(rq.
 Switching on this option results in a small loss of transfer efficiency.
 It has no effect on systems where \fBsplice\fR(2) is unavailable.
 .TP
+.BI \-J\  BYTES \fR,\ \fB\-\-pipe\-buffer\-size\  BYTES
+Attempt to set the size of the output pipe buffer to \fIBYTES\fR bytes.
+This will only have an effect if the output is a pipe, and will silently do
+nothing if the requested size cannot be achieved.
+If this option is not specified, and both the output and the first input are
+pipes, then the output pipe buffer size will automatically be increased to
+match the input pipe buffer, if it was smaller.
+.TP
 .B \-E, \-\-skip-errors
 Ignore read errors by attempting to skip past the offending sections.
 The corresponding parts of the output will be null bytes.
@@ -348,7 +356,6 @@ seekable, this option will have no effect other than to turn on
 Instead of transferring input data to standard output, discard it.
 This is equivalent to redirecting standard output to \fI/dev/null\fR,
 except that \fBwrite\fR(2) is never called.
-Implies \*(lq\fB\-\-no\-splice\fR\*(rq.
 .TP
 .BI \-U\  FILE \fR,\ \fB\-\-store\-and\-forward\  FILE
 Instead of passing data through immediately, do it in two stages - first
@@ -857,10 +864,10 @@ effective with small input files, and \*(lq\fB%nL\fR\*(rq may be a few lines
 out due to buffering within the pipeline itself.
 .PP
 Numbers passed to \*(lq\fB\-\-size\fR\*(rq, \*(lq\fB\-\-rate\-limit\fR\*(rq,
-\*(lq\fB\-\-buffer\-size\fR\*(rq, and \*(lq\fB\-\-error\-skip\-block\fR\*(rq
-may all be expressed as decimals if followed by a suffix, so for example
-\*(lq\fI\-\-size\~1.5G\fR\*(rq is equivalent to
-\*(lq\fI\-\-size\~1536M\fR\*(rq.
+\*(lq\fB\-\-buffer\-size\fR\*(rq, \*(lq\fB\-\-pipe\-buffer\-size\fR\*(rq,
+and \*(lq\fB\-\-error\-skip\-block\fR\*(rq may all be expressed as decimals
+if followed by a suffix, so for example \*(lq\fI\-\-size\~1.5G\fR\*(rq is
+equivalent to \*(lq\fI\-\-size\~1536M\fR\*(rq.
 .PP
 Numbers passed to \*(lq\fB\-\-interval\fR\*(rq and
 \*(lq\fB\-\-delay\-start\fR\*(rq may be integers or decimals, but may not

docs/pv.1.md

@@ -300,6 +300,15 @@ are explicitly switched on will be shown.
     option results in a small loss of transfer efficiency. It has no
     effect on systems where **splice**(2) is unavailable.
 
+**-J BYTES, \--pipe-buffer-size BYTES**
+
+:   Attempt to set the size of the output pipe buffer to *BYTES* bytes.
+    This will only have an effect if the output is a pipe, and will
+    silently do nothing if the requested size cannot be achieved. If
+    this option is not specified, and both the output and the first
+    input are pipes, then the output pipe buffer size will automatically
+    be increased to match the input pipe buffer, if it was smaller.
+
 **-E, \--skip-errors**
 
 :   Ignore read errors by attempting to skip past the offending
@@ -360,8 +369,7 @@ are explicitly switched on will be shown.
 
 :   Instead of transferring input data to standard output, discard it.
     This is equivalent to redirecting standard output to */dev/null*,
-    except that **write**(2) is never called. Implies
-    "**\--no-splice**".
+    except that **write**(2) is never called.
 
 **-U FILE, \--store-and-forward FILE**
 
@@ -814,9 +822,10 @@ small input files, and "**%nL**" may be a few lines out due to buffering
 within the pipeline itself.
 
 Numbers passed to "**\--size**", "**\--rate-limit**",
-"**\--buffer-size**", and "**\--error-skip-block**" may all be expressed
-as decimals if followed by a suffix, so for example "*\--size 1.5G*" is
-equivalent to "*\--size 1536M*".
+"**\--buffer-size**", "**\--pipe-buffer-size**", and
+"**\--error-skip-block**" may all be expressed as decimals if followed
+by a suffix, so for example "*\--size 1.5G*" is equivalent to
+"*\--size 1536M*".
 
 Numbers passed to "**\--interval**" and "**\--delay-start**" may be
 integers or decimals, but may not have a suffix.