[dpdk-dev] [PATCH v6] cfgfile: support looking up sections by index

[Rich Lane <rich.lane@bigswitch.com>]

This is useful when sections have duplicate names.

Signed-off-by: Rich Lane <rlane@bigswitch.com>
---
v5->v6:
- Reordered sectionname argument in comment.
v4->v5:
- Reordered sectionname argument.
v3->v4:
- Added section name return value.
- Updated API docs for other functions.
v2->v3
- Added check for index < 0.
v1->v2:
- Added new symbol to version script.

 lib/librte_cfgfile/rte_cfgfile.c           | 18 ++++++++++++++
 lib/librte_cfgfile/rte_cfgfile.h           | 39 ++++++++++++++++++++++++++++++
 lib/librte_cfgfile/rte_cfgfile_version.map |  6 +++++
 3 files changed, 63 insertions(+)

diff --git a/lib/librte_cfgfile/rte_cfgfile.c b/lib/librte_cfgfile/rte_cfgfile.c
index 1cd523f..75625a2 100644
--- a/lib/librte_cfgfile/rte_cfgfile.c
+++ b/lib/librte_cfgfile/rte_cfgfile.c
@@ -333,6 +333,24 @@ rte_cfgfile_section_entries(struct rte_cfgfile *cfg, const char *sectionname,
 	return i;
 }
 
+int
+rte_cfgfile_section_entries_by_index(struct rte_cfgfile *cfg, int index,
+		char *sectionname,
+		struct rte_cfgfile_entry *entries, int max_entries)
+{
+	int i;
+	const struct rte_cfgfile_section *sect;
+
+	if (index < 0 || index >= cfg->num_sections)
+		return -1;
+
+	sect = cfg->sections[index];
+	snprintf(sectionname, CFG_NAME_LEN, "%s", sect->name);
+	for (i = 0; i < max_entries && i < sect->num_entries; i++)
+		entries[i] = *sect->entries[i];
+	return i;
+}
+
 const char *
 rte_cfgfile_get_entry(struct rte_cfgfile *cfg, const char *sectionname,
 		const char *entryname)
diff --git a/lib/librte_cfgfile/rte_cfgfile.h b/lib/librte_cfgfile/rte_cfgfile.h
index d443782..834f828 100644
--- a/lib/librte_cfgfile/rte_cfgfile.h
+++ b/lib/librte_cfgfile/rte_cfgfile.h
@@ -126,6 +126,9 @@ int rte_cfgfile_has_section(struct rte_cfgfile *cfg, const char *sectionname);
 /**
 * Get number of entries in given config file section
 *
+* If multiple sections have the given name this function operates on the
+* first one.
+*
 * @param cfg
 *   Config file
 * @param sectionname
@@ -138,6 +141,9 @@ int rte_cfgfile_section_num_entries(struct rte_cfgfile *cfg,
 
 /** Get section entries as key-value pairs
 *
+* If multiple sections have the given name this function operates on the
+* first one.
+*
 * @param cfg
 *   Config file
 * @param sectionname
@@ -155,8 +161,38 @@ int rte_cfgfile_section_entries(struct rte_cfgfile *cfg,
 	struct rte_cfgfile_entry *entries,
 	int max_entries);
 
+/** Get section entries as key-value pairs
+*
+* The index of a section is the same as the index of its name in the
+* result of rte_cfgfile_sections. This API can be used when there are
+* multiple sections with the same name.
+*
+* @param cfg
+*   Config file
+* @param index
+*   Section index
+* @param sectionname
+*   Pre-allocated string of at least CFG_NAME_LEN characters where the
+*   section name is stored after successful invocation.
+* @param entries
+*   Pre-allocated array of at least max_entries entries where the section
+*   entries are stored as key-value pair after successful invocation
+* @param max_entries
+*   Maximum number of section entries to be stored in entries array
+* @return
+*   Number of entries populated on success, negative error code otherwise
+*/
+int rte_cfgfile_section_entries_by_index(struct rte_cfgfile *cfg,
+	int index,
+	char *sectionname,
+	struct rte_cfgfile_entry *entries,
+	int max_entries);
+
 /** Get value of the named entry in named config file section
 *
+* If multiple sections have the given name this function operates on the
+* first one.
+*
 * @param cfg
 *   Config file
 * @param sectionname
@@ -172,6 +208,9 @@ const char *rte_cfgfile_get_entry(struct rte_cfgfile *cfg,
 
 /** Check if given entry exists in named config file section
 *
+* If multiple sections have the given name this function operates on the
+* first one.
+*
 * @param cfg
 *   Config file
 * @param sectionname
diff --git a/lib/librte_cfgfile/rte_cfgfile_version.map b/lib/librte_cfgfile/rte_cfgfile_version.map
index bf6c6fd..f6a27a9 100644
--- a/lib/librte_cfgfile/rte_cfgfile_version.map
+++ b/lib/librte_cfgfile/rte_cfgfile_version.map
@@ -13,3 +13,9 @@ DPDK_2.0 {
 
 	local: *;
 };
+
+DPDK_2.3 {
+	global:
+
+	rte_cfgfile_section_entries_by_index;
+} DPDK_2.0;
-- 
1.9.1