cfgfile: support runtime modification

Extend existing cfgfile library with providing new API functions:

rte_cfgfile_create() - create new cfgfile object
rte_cfgfile_add_section() - add new section to existing cfgfile
object
rte_cfgfile_add_entry() - add new entry to existing cfgfile
object in specified section
rte_cfgfile_set_entry() - update existing entry in cfgfile object
rte_cfgfile_save() - save existing cfgfile object to INI file

This modification allows to create a cfgfile on
runtime and opens up the possibility to have applications
dynamically build up a proper DPDK configuration, rather than having
to have a pre-existing one.

Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/lib/librte_cfgfile/rte_cfgfile.c b/lib/librte_cfgfile/rte_cfgfile.c
index 39f61e5..ad9bb2e 100644 (file)
--- a/lib/librte_cfgfile/rte_cfgfile.c
+++ b/lib/librte_cfgfile/rte_cfgfile.c
@@ -120,6 +120,36 @@ _get_section(struct rte_cfgfile *cfg, const char *sectionname)
        return NULL;
 }
 
+static int
+_add_entry(struct rte_cfgfile_section *section, const char *entryname,
+               const char *entryvalue)
+{
+       /* resize entry structure if we don't have room for more entries */
+       if (section->num_entries == section->allocated_entries) {
+               struct rte_cfgfile_entry *n_entries = realloc(
+                               section->entries,
+                               sizeof(struct rte_cfgfile_entry) *
+                               ((section->allocated_entries) +
+                                               CFG_ALLOC_ENTRY_BATCH));
+
+               if (n_entries == NULL)
+                       return -ENOMEM;
+
+               section->entries = n_entries;
+               section->allocated_entries += CFG_ALLOC_ENTRY_BATCH;
+       }
+       /* fill up entry fields with key name and value */
+       struct rte_cfgfile_entry *curr_entry =
+                                       &section->entries[section->num_entries];
+
+       snprintf(curr_entry->name, sizeof(curr_entry->name), "%s", entryname);
+       snprintf(curr_entry->value,
+                               sizeof(curr_entry->value), "%s", entryvalue);
+       section->num_entries++;
+
+       return 0;
+}
+
 static int
 rte_cfgfile_check_params(const struct rte_cfgfile_parameters *params)
 {
@@ -346,6 +376,162 @@ error2:
        return NULL;
 }
 
+struct rte_cfgfile *
+rte_cfgfile_create(int flags)
+{
+       int i;
+       struct rte_cfgfile *cfg = NULL;
+
+       cfg = malloc(sizeof(*cfg));
+
+       if (cfg == NULL)
+               return NULL;
+
+       cfg->flags = flags;
+       cfg->num_sections = 0;
+
+       /* allocate first batch of sections and entries */
+       cfg->sections = malloc(sizeof(struct rte_cfgfile_section) *
+                       CFG_ALLOC_SECTION_BATCH);
+
+       if (cfg->sections == NULL)
+               return NULL;
+
+       cfg->allocated_sections = CFG_ALLOC_SECTION_BATCH;
+
+       for (i = 0; i < CFG_ALLOC_SECTION_BATCH; i++) {
+               cfg->sections[i].entries = malloc(sizeof(
+                       struct rte_cfgfile_entry) * CFG_ALLOC_ENTRY_BATCH);
+
+               if (cfg->sections[i].entries == NULL)
+                       return NULL;
+
+               cfg->sections[i].num_entries = 0;
+               cfg->sections[i].allocated_entries = CFG_ALLOC_ENTRY_BATCH;
+       }
+
+       if (flags & CFG_FLAG_GLOBAL_SECTION)
+               rte_cfgfile_add_section(cfg, "GLOBAL");
+       return cfg;
+}
+
+int
+rte_cfgfile_add_section(struct rte_cfgfile *cfg, const char *sectionname)
+{
+       int i;
+
+       if (cfg == NULL)
+               return -EINVAL;
+
+       if (sectionname == NULL)
+               return -EINVAL;
+
+       /* resize overall struct if we don't have room for more sections */
+       if (cfg->num_sections == cfg->allocated_sections) {
+
+               struct rte_cfgfile_section *n_sections =
+                               realloc(cfg->sections,
+                               sizeof(struct rte_cfgfile_section) *
+                               ((cfg->allocated_sections) +
+                               CFG_ALLOC_SECTION_BATCH));
+
+               if (n_sections == NULL)
+                       return -ENOMEM;
+
+               for (i = 0; i < CFG_ALLOC_SECTION_BATCH; i++) {
+                       n_sections[i + cfg->allocated_sections].num_entries = 0;
+                       n_sections[i +
+                                cfg->allocated_sections].allocated_entries = 0;
+                       n_sections[i + cfg->allocated_sections].entries = NULL;
+               }
+               cfg->sections = n_sections;
+               cfg->allocated_sections += CFG_ALLOC_SECTION_BATCH;
+       }
+
+       snprintf(cfg->sections[cfg->num_sections].name,
+                       sizeof(cfg->sections[0].name), "%s", sectionname);
+       cfg->sections[cfg->num_sections].num_entries = 0;
+       cfg->num_sections++;
+
+       return 0;
+}
+
+int rte_cfgfile_add_entry(struct rte_cfgfile *cfg,
+               const char *sectionname, const char *entryname,
+               const char *entryvalue)
+{
+       int ret;
+
+       if ((cfg == NULL) || (sectionname == NULL) || (entryname == NULL)
+                       || (entryvalue == NULL))
+               return -EINVAL;
+
+       if (rte_cfgfile_has_entry(cfg, sectionname, entryname) != 0)
+               return -EEXIST;
+
+       /* search for section pointer by sectionname */
+       struct rte_cfgfile_section *curr_section = _get_section(cfg,
+                                                               sectionname);
+       if (curr_section == NULL)
+               return -EINVAL;
+
+       ret = _add_entry(curr_section, entryname, entryvalue);
+
+       return ret;
+}
+
+int rte_cfgfile_set_entry(struct rte_cfgfile *cfg, const char *sectionname,
+               const char *entryname, const char *entryvalue)
+{
+       int i;
+
+       if ((cfg == NULL) || (sectionname == NULL) || (entryname == NULL))
+               return -EINVAL;
+
+       /* search for section pointer by sectionname */
+       struct rte_cfgfile_section *curr_section = _get_section(cfg,
+                                                               sectionname);
+       if (curr_section == NULL)
+               return -EINVAL;
+
+       if (entryvalue == NULL)
+               entryvalue = "";
+
+       for (i = 0; i < curr_section->num_entries; i++)
+               if (!strcmp(curr_section->entries[i].name, entryname)) {
+                       snprintf(curr_section->entries[i].value,
+                                       sizeof(curr_section->entries[i].value),
+                                                       "%s", entryvalue);
+                       return 0;
+               }
+       printf("Error - entry name doesn't exist\n");
+       return -EINVAL;
+}
+
+int rte_cfgfile_save(struct rte_cfgfile *cfg, const char *filename)
+{
+       int i, j;
+
+       if ((cfg == NULL) || (filename == NULL))
+               return -EINVAL;
+
+       FILE *f = fopen(filename, "w");
+
+       if (f == NULL)
+               return -EINVAL;
+
+       for (i = 0; i < cfg->num_sections; i++) {
+               fprintf(f, "[%s]\n", cfg->sections[i].name);
+
+               for (j = 0; j < cfg->sections[i].num_entries; j++) {
+                       fprintf(f, "%s=%s\n",
+                                       cfg->sections[i].entries[j].name,
+                                       cfg->sections[i].entries[j].value);
+               }
+       }
+       return fclose(f);
+}
+
 int rte_cfgfile_close(struct rte_cfgfile *cfg)
 {
        int i;

diff --git a/lib/librte_cfgfile/rte_cfgfile.h b/lib/librte_cfgfile/rte_cfgfile.h
index 35dc419..17f7275 100644 (file)
--- a/lib/librte_cfgfile/rte_cfgfile.h
+++ b/lib/librte_cfgfile/rte_cfgfile.h
@@ -120,6 +120,82 @@ struct rte_cfgfile *rte_cfgfile_load(const char *filename, int flags);
 struct rte_cfgfile *rte_cfgfile_load_with_params(const char *filename,
        int flags, const struct rte_cfgfile_parameters *params);
 
+/**
+ * Create new cfgfile instance with empty sections and entries
+ *
+ * @param flags
+ *   - CFG_FLAG_GLOBAL_SECTION
+ *     Indicates that the file supports key value entries before the first
+ *     defined section.  These entries can be accessed in the "GLOBAL"
+ *     section.
+ *   - CFG_FLAG_EMPTY_VALUES
+ *     Indicates that file supports key value entries where the value can
+ *     be zero length (e.g., "key=").
+ * @return
+ *   Handle to cfgfile instance on success, NULL otherwise
+ */
+struct rte_cfgfile *rte_cfgfile_create(int flags);
+
+/**
+ * Add section in cfgfile instance.
+ *
+ * @param cfg
+ *   Pointer to the cfgfile structure.
+ * @param sectionname
+ *   Section name which will be add to cfgfile.
+ * @return
+ *   0 on success, -ENOMEM if can't add section
+ */
+int
+rte_cfgfile_add_section(struct rte_cfgfile *cfg, const char *sectionname);
+
+/**
+ * Add entry to specified section in cfgfile instance.
+ *
+ * @param cfg
+ *   Pointer to the cfgfile structure.
+ * @param sectionname
+ *   Given section name to add an entry.
+ * @param entryname
+ *   Entry name to add.
+ * @param entryvalue
+ *   Entry value to add.
+ * @return
+ *   0 on success, -EEXIST if entry already exist, -EINVAL if bad argument
+ */
+int rte_cfgfile_add_entry(struct rte_cfgfile *cfg,
+               const char *sectionname, const char *entryname,
+               const char *entryvalue);
+
+/**
+ * Update value of specified entry name in given section in config file
+ *
+ * @param cfg
+ *   Config file
+ * @param sectionname
+ *   Section name
+ * @param entryname
+ *   Entry name to look for the value change
+ * @param entryvalue
+ *   New entry value. Can be also an empty string if CFG_FLAG_EMPTY_VALUES = 1
+ * @return
+ *   0 on success, -EINVAL if bad argument
+ */
+int rte_cfgfile_set_entry(struct rte_cfgfile *cfg, const char *sectionname,
+               const char *entryname, const char *entryvalue);
+
+/**
+ * Save object cfgfile to file on disc
+ *
+ * @param cfg
+ *   Config file structure
+ * @param filename
+ *   File name to save data
+ * @return
+ *   0 on success, errno otherwise
+ */
+int rte_cfgfile_save(struct rte_cfgfile *cfg, const char *filename);
+
 /**
 * Get number of sections in config file
 *

diff --git a/lib/librte_cfgfile/rte_cfgfile_version.map b/lib/librte_cfgfile/rte_cfgfile_version.map
index 5fe60f7..cc4a11f 100644 (file)
--- a/lib/librte_cfgfile/rte_cfgfile_version.map
+++ b/lib/librte_cfgfile/rte_cfgfile_version.map
@@ -27,3 +27,14 @@ DPDK_17.05 {
     rte_cfgfile_load_with_params;
 
 } DPDK_16.04;
+
+DPDK_17.11 {
+       global:
+
+       rte_cfgfile_add_entry;
+       rte_cfgfile_add_section;
+       rte_cfgfile_create;
+       rte_cfgfile_save;
+       rte_cfgfile_set_entry;
+
+} DPDK_17.05;