UCS/CONFIG: let ucx support configuration file

configure.ac

@@ -109,6 +109,26 @@ AS_IF([${LN_S} --relative symlinktest 2>/dev/null],
 #
 AC_DEFINE_UNQUOTED([UCX_CONFIGURE_FLAGS], ["$config_flags"], [UCX configure flags])
 
+#
+# File path for ucx conf
+# ./configure                                        is /etc/ucx.conf
+# ./configure --prefix=/usr                          is /etc/ucx.conf
+# ./configure --prefix=/usr/local                    is /usr/local/etc/ucx.conf
+# ./configure --prefix=/usr/local --sysconfdir=/etc  is /etc/ucx.conf
+#
+case "$prefix" in
+    NONE | /usr)
+        case "$sysconfdir" in
+            '${prefix}/etc')
+                sysconfdir=/etc
+                ;;
+        esac
+        ;;
+esac
+
+SYSCONFDIR_TMP="`eval echo $sysconfdir`"
+AC_SUBST([ucx_conf_file], [${SYSCONFDIR_TMP}/ucx.conf])
+AC_DEFINE_UNQUOTED([UCX_CONF_FILE], ["$ucx_conf_file"], [ucx conf file])
 
 #
 # Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
@@ -391,6 +411,7 @@ AC_MSG_NOTICE([Building documents only])
 [
 AC_MSG_NOTICE([UCX build configuration:])
 AC_MSG_NOTICE([      Build prefix:   ${prefix}])
+AC_MSG_NOTICE([       config file:   ${ucx_conf_file}])
 AC_MSG_NOTICE([Preprocessor flags:   ${BASE_CPPFLAGS}])
 AC_MSG_NOTICE([        C compiler:   ${CC} ${BASE_CFLAGS}])
 AC_MSG_NOTICE([      C++ compiler:   ${CXX} ${BASE_CXXFLAGS}])

src/ucs/Makefile.am

@@ -20,6 +20,7 @@ nobase_dist_libucs_la_HEADERS = \
 	algorithm/qsort_r.h \
 	async/async_fwd.h \
 	config/global_opts.h \
+	config/ini.h \
 	config/parser.h \
 	config/types.h \
 	datastruct/callbackq.h \
@@ -122,6 +123,7 @@ libucs_la_SOURCES = \
 	async/thread.c \
 	config/global_opts.c \
 	config/ucm_opts.c \
+	config/ini.c \
 	config/parser.c \
 	datastruct/arbiter.c \
 	datastruct/callbackq.c \

src/ucs/config/ini.c

@@ -0,0 +1,344 @@
+/* inih -- simple .INI file parser
+
+SPDX-License-Identifier: BSD-3-Clause
+
+Copyright (C) 2009-2020, Ben Hoyt
+
+inih is released under the New BSD license (see LICENSE.txt). Go to the project
+home page for more info:
+
+https://github.com/benhoyt/inih
+
+*/
+
+/*
+An example without section
+test.ini
+##########
+# Test config file for ini example
+version = 0.0.1       # verison
+     name    = jack        # name
+##########
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "ini.h"
+typedef struct {
+    char* version;
+    char* name;
+} config;
+static int handler(void* user, const char* section, const char* name,
+                   const char* value) {
+    config* conf = (config*)user;
+    #define MATCH(n) (strcmp(section, "") == 0 && strcmp(name, n) == 0)
+    if (MATCH("version")) {
+        conf->version = strdup(value);
+    } else if (MATCH("name")) {
+        conf->name = strdup(value);
+    } else {
+        return 0;
+    }
+    return 1;
+}
+int main() {
+    config conf;
+    if (ini_parse("test.ini", handler, &conf) < 0) {
+        printf("Can't load test.ini %s\n", strerror(errno));
+        return 1;
+    }
+    printf("Config loaded from test.int: version=%s, name=%s\n",
+            conf.name, conf.version);
+    free(conf.version);
+    free(conf.name);
+    return 0;
+}
+
+*/
+
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+
+#include "ini.h"
+
+#if !INI_USE_STACK
+#if INI_CUSTOM_ALLOCATOR
+#include <stddef.h>
+void* ini_malloc(size_t size);
+void ini_free(void* ptr);
+void* ini_realloc(void* ptr, size_t size);
+#else
+#include <stdlib.h>
+#define ini_malloc malloc
+#define ini_free free
+#define ini_realloc realloc
+#endif
+#endif
+
+#define MAX_SECTION 50
+#define MAX_NAME 50
+
+/* Used by ini_parse_string() to keep track of string parsing state. */
+typedef struct {
+    const char* ptr;
+    size_t num_left;
+} ini_parse_string_ctx;
+
+/* Strip whitespace chars off end of given string, in place. Return s. */
+static char* rstrip(char* s)
+{
+    char* p = s + strlen(s);
+    while (p > s && isspace((unsigned char)(*--p)))
+        *p = '\0';
+    return s;
+}
+
+/* Return pointer to first non-whitespace char in given string. */
+static char* lskip(const char* s)
+{
+    while (*s && isspace((unsigned char)(*s)))
+        s++;
+    return (char*)s;
+}
+
+/* Return pointer to first char (of chars) or inline comment in given string,
+   or pointer to NUL at end of string if neither found. Inline comment must
+   be prefixed by a whitespace character to register as a comment. */
+static char* find_chars_or_comment(const char* s, const char* chars)
+{
+#if INI_ALLOW_INLINE_COMMENTS
+    int was_space = 0;
+    while (*s && (!chars || !strchr(chars, *s)) &&
+           !(was_space && strchr(INI_INLINE_COMMENT_PREFIXES, *s))) {
+        was_space = isspace((unsigned char)(*s));
+        s++;
+    }
+#else
+    while (*s && (!chars || !strchr(chars, *s))) {
+        s++;
+    }
+#endif
+    return (char*)s;
+}
+
+/* Similar to strncpy, but ensures dest (size bytes) is
+   NUL-terminated, and doesn't pad with NULs. */
+static char* strncpy0(char* dest, const char* src, size_t size)
+{
+    /* Could use strncpy internally, but it causes gcc warnings (see issue #91) */
+    size_t i;
+    for (i = 0; i < size - 1 && src[i]; i++)
+        dest[i] = src[i];
+    dest[i] = '\0';
+    return dest;
+}
+
+/* See documentation in header file. */
+int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
+                     void* user)
+{
+    /* Uses a fair bit of stack (use heap instead if you need to) */
+#if INI_USE_STACK
+    char line[INI_MAX_LINE];
+    int max_line = INI_MAX_LINE;
+#else
+    char* line;
+    size_t max_line = INI_INITIAL_ALLOC;
+#endif
+#if INI_ALLOW_REALLOC && !INI_USE_STACK
+    char* new_line;
+    size_t offset;
+#endif
+    char section[MAX_SECTION] = "";
+    char prev_name[MAX_NAME] = "";
+
+    char* start;
+    char* end;
+    char* name;
+    char* value;
+    int lineno = 0;
+    int error = 0;
+
+#if !INI_USE_STACK
+    line = (char*)ini_malloc(INI_INITIAL_ALLOC);
+    if (!line) {
+        return -2;
+    }
+#endif
+
+#if INI_HANDLER_LINENO
+#define HANDLER(u, s, n, v) handler(u, s, n, v, lineno)
+#else
+#define HANDLER(u, s, n, v) handler(u, s, n, v)
+#endif
+
+    /* Scan through stream line by line */
+    while (reader(line, (int)max_line, stream) != NULL) {
+#if INI_ALLOW_REALLOC && !INI_USE_STACK
+        offset = strlen(line);
+        while (offset == max_line - 1 && line[offset - 1] != '\n') {
+            max_line *= 2;
+            if (max_line > INI_MAX_LINE)
+                max_line = INI_MAX_LINE;
+            new_line = ini_realloc(line, max_line);
+            if (!new_line) {
+                ini_free(line);
+                return -2;
+            }
+            line = new_line;
+            if (reader(line + offset, (int)(max_line - offset), stream) == NULL)
+                break;
+            if (max_line >= INI_MAX_LINE)
+                break;
+            offset += strlen(line + offset);
+        }
+#endif
+
+        lineno++;
+
+        start = line;
+#if INI_ALLOW_BOM
+        if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
+            (unsigned char)start[1] == 0xBB &&
+            (unsigned char)start[2] == 0xBF) {
+            start += 3;
+        }
+#endif
+        start = lskip(rstrip(start));
+
+        if (strchr(INI_START_COMMENT_PREFIXES, *start)) {
+            /* Start-of-line comment */
+        }
+#if INI_ALLOW_MULTILINE
+        else if (*prev_name && *start && start > line) {
+            /* Non-blank line with leading whitespace, treat as continuation
+               of previous name's value (as per Python configparser). */
+            if (!HANDLER(user, section, prev_name, start) && !error)
+                error = lineno;
+        }
+#endif
+        else if (*start == '[') {
+            /* A "[section]" line */
+            end = find_chars_or_comment(start + 1, "]");
+            if (*end == ']') {
+                *end = '\0';
+                strncpy0(section, start + 1, sizeof(section));
+                *prev_name = '\0';
+#if INI_CALL_HANDLER_ON_NEW_SECTION
+                if (!HANDLER(user, section, NULL, NULL) && !error)
+                    error = lineno;
+#endif
+            }
+            else if (!error) {
+                /* No ']' found on section line */
+                error = lineno;
+            }
+        }
+        else if (*start) {
+            /* Not a comment, must be a name[=:]value pair */
+            end = find_chars_or_comment(start, "=:");
+            if (*end == '=' || *end == ':') {
+                *end = '\0';
+                name = rstrip(start);
+                value = end + 1;
+#if INI_ALLOW_INLINE_COMMENTS
+                end = find_chars_or_comment(value, NULL);
+                if (*end)
+                    *end = '\0';
+#endif
+                value = lskip(value);
+                rstrip(value);
+
+                /* Valid name[=:]value pair found, call handler */
+                strncpy0(prev_name, name, sizeof(prev_name));
+                if (!HANDLER(user, section, name, value) && !error)
+                    error = lineno;
+            }
+            else if (!error) {
+                /* No '=' or ':' found on name[=:]value line */
+#if INI_ALLOW_NO_VALUE
+                *end = '\0';
+                name = rstrip(start);
+                if (!HANDLER(user, section, name, NULL) && !error)
+                    error = lineno;
+#else
+                error = lineno;
+#endif
+            }
+        }
+
+#if INI_STOP_ON_FIRST_ERROR
+        if (error)
+            break;
+#endif
+    }
+
+#if !INI_USE_STACK
+    ini_free(line);
+#endif
+
+    return error;
+}
+
+/* See documentation in header file. */
+int ini_parse_file(FILE* file, ini_handler handler, void* user)
+{
+    return ini_parse_stream((ini_reader)fgets, file, handler, user);
+}
+
+/* See documentation in header file. */
+int ini_parse(const char* filename, ini_handler handler, void* user)
+{
+    FILE* file;
+    int error;
+
+    file = fopen(filename, "r");
+    if (!file)
+        return -1;
+    error = ini_parse_file(file, handler, user);
+    fclose(file);
+    return error;
+}
+
+/* An ini_reader function to read the next line from a string buffer. This
+   is the fgets() equivalent used by ini_parse_string(). */
+static char* ini_reader_string(char* str, int num, void* stream) {
+    ini_parse_string_ctx* ctx = (ini_parse_string_ctx*)stream;
+    const char* ctx_ptr = ctx->ptr;
+    size_t ctx_num_left = ctx->num_left;
+    char* strp = str;
+    char c;
+
+    if (ctx_num_left == 0 || num < 2)
+        return NULL;
+
+    while (num > 1 && ctx_num_left != 0) {
+        c = *ctx_ptr++;
+        ctx_num_left--;
+        *strp++ = c;
+        if (c == '\n')
+            break;
+        num--;
+    }
+
+    *strp = '\0';
+    ctx->ptr = ctx_ptr;
+    ctx->num_left = ctx_num_left;
+    return str;
+}
+
+/* See documentation in header file. */
+int ini_parse_string(const char* string, ini_handler handler, void* user) {
+    ini_parse_string_ctx ctx;
+
+    ctx.ptr = string;
+    ctx.num_left = strlen(string);
+    return ini_parse_stream((ini_reader)ini_reader_string, &ctx, handler,
+                            user);
+}