From: Sebastian Harl <sh@tokkee.org>
Date: Tue, 4 Feb 2014 22:31:36 +0000 (+0100)
Subject: sysdb: Hide implementation details in the "input" module.
X-Git-Tag: sysdb-0.1.0~223
X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=commitdiff_plain;h=78fe39914ac0b2faa559a42eff7e9662085c335d

sysdb: Hide implementation details in the "input" module.

… and added some overview documentation about how the "input" module works and
interacts with the other subsystems.
---

diff --git a/src/tools/sysdb/input.c b/src/tools/sysdb/input.c
index c42390f..f115e3e 100644
--- a/src/tools/sysdb/input.c
+++ b/src/tools/sysdb/input.c
@@ -25,6 +25,21 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/*
+ * This module implements the core of the command line tool. It handles all
+ * input from the user and the remote server, interacting with the scanner and
+ * command handling as needed.
+ *
+ * The main loop is managed by the flex scanner which parses the user input.
+ * It will call into this module (using sdb_input_readline()) whenever it
+ * needs further input to continue parsing. Whenever it finds a full query
+ * (terminated by a semicolon), it will hand the query back to this module
+ * (using sdb_input_exec_query()) which will then execute it.
+ *
+ * Most of the process life-time will be spend waiting for input. User input
+ * and (asynchronous) server replies are handled at the same time.
+ */
+
 #if HAVE_CONFIG_H
 #	include "config.h"
 #endif /* HAVE_CONFIG_H */
@@ -61,6 +76,8 @@
 #	endif
 #endif /* READLINEs */
 
+extern int yylex(void);
+
 /*
  * public variables
  */
@@ -189,6 +206,13 @@ sdb_input_init(sdb_input_t *input)
 	return 0;
 } /* sdb_input_init */
 
+int
+sdb_input_mainloop(void)
+{
+	yylex();
+	return 0;
+} /* sdb_input_mainloop */
+
 ssize_t
 sdb_input_readline(char *buf, int *n_chars, size_t max_chars)
 {
diff --git a/src/tools/sysdb/input.h b/src/tools/sysdb/input.h
index 80f1bb5..40bd7c0 100644
--- a/src/tools/sysdb/input.h
+++ b/src/tools/sysdb/input.h
@@ -56,6 +56,18 @@ extern sdb_input_t *sysdb_input;
 int
 sdb_input_init(sdb_input_t *input);
 
+/*
+ * sdb_input_mainloop:
+ * Wait for and handle all user and server input until end-of-file is read
+ * from the user (on the standard input channel).
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_input_mainloop(void);
+
 /*
  * sdb_input_readline:
  * This function is supposed to be used with a flex scanner's YY_INPUT. It
diff --git a/src/tools/sysdb/main.c b/src/tools/sysdb/main.c
index 9b575cc..bc34a48 100644
--- a/src/tools/sysdb/main.c
+++ b/src/tools/sysdb/main.c
@@ -78,8 +78,6 @@
 #	define DEFAULT_SOCKET "unix:"LOCALSTATEDIR"/run/sysdbd.sock"
 #endif
 
-extern int yylex(void);
-
 static void
 exit_usage(char *name, int status)
 {
@@ -242,7 +240,7 @@ main(int argc, char **argv)
 
 	input.input = sdb_strbuf_create(2048);
 	sdb_input_init(&input);
-	yylex();
+	sdb_input_mainloop();
 
 	if (hist_file[0] != '\0') {
 		errno = 0;