debuginfod client API: add get/set user_data functions

Add a pair of functions to associate a void* parameter with a client
object.  Requested by GDB team as a way to pass file names and such
user-interface data through to a progressfn callback.

Signed-off-by: Frank Ch. Eigler <fche@redhat.com>

5 files changed, 42 insertions, 5 deletions

diff --git a/doc/ChangeLog b/doc/ChangeLog
index 76445412..16b0e99f 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,9 @@
+2020-03-22  Frank Ch. Eigler  <fche@redhat.com>
+
+	* debuginfod_get_user.3, _set_user.3: New functions, documented ...
+	* debuginfod_find_debuginfo.3: ... here.
+	* Makefile.am (notrans_dist_*_man3): List all debuginfod .3 functions.
+
 2020-02-25  Frank Ch. Eigler  <fche@redhat.com>
 
 	* debuginfod.8: Note that -R works just like -Z.rpm .
diff --git a/doc/Makefile.am b/doc/Makefile.am
index b5db01ff..87d1fee0 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,7 +1,7 @@
 ## Process this file with automake to create Makefile.in
 ## Configure input file for elfutils.
 ##
-## Copyright (C) 1996-2001, 2002, 2005, 2019 Red Hat, Inc.
+## Copyright (C) 1996-2001, 2002, 2005, 2019-2020 Red Hat, Inc.
 ## This file is part of elfutils.
 ##
 ## This file is free software; you can redistribute it and/or modify
@@ -24,7 +24,14 @@ notrans_dist_man1_MANS=
 
 if DEBUGINFOD
 notrans_dist_man8_MANS += debuginfod.8
-notrans_dist_man3_MANS += debuginfod_find_debuginfo.3 debuginfod_find_source.3 debuginfod_find_executable.3 debuginfod_set_progressfn.3
+notrans_dist_man3_MANS += debuginfod_begin.3
+notrans_dist_man3_MANS += debuginfod_end.3
+notrans_dist_man3_MANS += debuginfod_find_debuginfo.3
+notrans_dist_man3_MANS += debuginfod_find_executable.3
+notrans_dist_man3_MANS += debuginfod_find_source.3
+notrans_dist_man3_MANS += debuginfod_get_user_data.3
+notrans_dist_man3_MANS += debuginfod_set_progressfn.3
+notrans_dist_man3_MANS += debuginfod_set_user_data.3
 notrans_dist_man1_MANS += debuginfod-find.1
 endif
 
diff --git a/doc/debuginfod_find_debuginfo.3 b/doc/debuginfod_find_debuginfo.3
index f9e770b0..29706513 100644
--- a/doc/debuginfod_find_debuginfo.3
+++ b/doc/debuginfod_find_debuginfo.3
@@ -21,9 +21,15 @@ debuginfod_find_debuginfo \- request debuginfo from debuginfod
 .nf
 .B #include <elfutils/debuginfod.h>
 .PP
+Link with \fB-ldebuginfod\fP.
+
+CONNECTION HANDLE
+
 .BI "debuginfod_client *debuginfod_begin(void);"
 .BI "void debuginfod_end(debuginfod_client *" client ");"
 
+LOOKUP FUNCTIONS
+
 .BI "int debuginfod_find_debuginfo(debuginfod_client *" client ","
 .BI "                              const unsigned char *" build_id ","
 .BI "                              int " build_id_len ","
@@ -38,12 +44,15 @@ debuginfod_find_debuginfo \- request debuginfo from debuginfod
 .BI "                           const char *" filename ","
 .BI "                           char ** " path ");"
 
+OPTIONAL FUNCTIONS
+
 .BI "typedef int (*debuginfod_progressfn_t)(debuginfod_client *" client ","
 .BI "                                       long a, long b);"
 .BI "void debuginfod_set_progressfn(debuginfod_client *" client ","
 .BI "                               debuginfod_progressfn_t " progressfn ");"
-
-Link with \fB-ldebuginfod\fP.
+.BI "void debuginfod_set_user_data(debuginfod_client *" client ","
+.BI "                              void *" data ");"
+.BI "void* debuginfod_get_user_data(debuginfod_client *" client ");"
 
 .SH DESCRIPTION
 
@@ -102,7 +111,12 @@ to the client cache and a file descriptor to that file is returned.
 The caller needs to \fBclose\fP() this descriptor.  Otherwise, a
 negative error code is returned.
 
-.SH "PROGRESS CALLBACK"
+.SH "OPTIONAL FUNCTIONS"
+
+A small number of optional functions are available to tune or query
+the operation of the debuginfod client.
+
+.SS "PROGRESS CALLBACK"
 
 As the \fBdebuginfod_find_*\fP() functions may block for seconds or
 longer, a progress callback function is called periodically, if
@@ -125,6 +139,14 @@ continue the work, or any other value to stop work as soon as
 possible.  Consequently, the \fBdebuginfod_find_*\fP() function will
 likely return with an error, but might still succeed.
 
+.SS "USER DATA POINTER"
+
+A single \fIvoid *\fP pointer associated with the connection handle
+may be set any time via
+.BR \%debuginfod_set_user_data () ,
+and retrieved via
+.BR \%debuginfod_get_user_data () .
+The value is undefined if unset.
 
 .SH "CACHE"
 If the query is successful, the \fBdebuginfod_find_*\fP() functions save
diff --git a/doc/debuginfod_get_user_data.3 b/doc/debuginfod_get_user_data.3
new file mode 100644
index 00000000..16279936
--- /dev/null
+++ b/doc/debuginfod_get_user_data.3
@@ -0,0 +1 @@
+.so man3/debuginfod_find_debuginfo.3
diff --git a/doc/debuginfod_set_user_data.3 b/doc/debuginfod_set_user_data.3
new file mode 100644
index 00000000..16279936
--- /dev/null
+++ b/doc/debuginfod_set_user_data.3
@@ -0,0 +1 @@
+.so man3/debuginfod_find_debuginfo.3