common: added config-parser

3 files changed, 267 insertions, 0 deletions

diff --git a/src/common/config-parser.c b/src/common/config-parser.c
new file mode 100644
index 0000000..9361908
--- /dev/null
+++ b/src/common/config-parser.c
@@ -0,0 +1,238 @@
+/*
+ * blogc: A blog compiler.
+ * Copyright (C) 2014-2016 Rafael G. Martins <rafael@rafaelmartins.eng.br>
+ *
+ * This program can be distributed under the terms of the BSD License.
+ * See the file LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <stdlib.h>
+#include "error.h"
+#include "utils.h"
+#include "config-parser.h"
+
+
+typedef enum {
+    CONFIG_START = 1,
+    CONFIG_SECTION_START,
+    CONFIG_SECTION,
+    CONFIG_SECTION_KEY,
+    CONFIG_SECTION_VALUE_START,
+    CONFIG_SECTION_VALUE,
+} bc_configparser_state_t;
+
+
+bc_config_t*
+bc_config_parse(const char *src, size_t src_len, bc_error_t **err)
+{
+    if (err != NULL && *err != NULL)
+        return NULL;
+
+    size_t current = 0;
+    size_t start = 0;
+
+    bc_trie_t *section = NULL;
+
+    char *section_name = NULL;
+    char *key = NULL;
+    char *value = NULL;
+
+    bc_config_t *rv = bc_malloc(sizeof(bc_config_t));
+    rv->root = bc_trie_new((bc_free_func_t) bc_trie_free);
+
+    bc_configparser_state_t state = CONFIG_START;
+
+    while (current < src_len) {
+        char c = src[current];
+        bool is_last = current == src_len - 1;
+
+        switch (state) {
+
+            case CONFIG_START:
+                if (c == '#' || c == ';') {
+                    while (current < src_len) {
+                        if (src[current] == '\r' || src[current] == '\n')
+                            break;
+                        current++;
+                    }
+                    break;
+                }
+                if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
+                    break;
+                if (c == '[') {
+                    state = CONFIG_SECTION_START;
+                    break;
+                }
+                if (section != NULL) {
+                    start = current;
+                    state = CONFIG_SECTION_KEY;
+                    continue;
+                }
+                if (err != NULL)
+                    *err = bc_error_new_printf(BC_ERROR_CONFIG_PARSER,
+                        "File must start with section");
+                break;
+
+            case CONFIG_SECTION_START:
+                start = current;
+                state = CONFIG_SECTION;
+                break;
+
+            case CONFIG_SECTION:
+                if (c == ']') {
+                    section_name = bc_strndup(src + start, current - start);
+                    section = bc_trie_new(free);
+                    bc_trie_insert(rv->root, section_name, section);
+                    free(section_name);
+                    section_name = NULL;
+                    state = CONFIG_START;
+                    break;
+                }
+                if (c != '\r' && c != '\n')
+                    break;
+                if (err != NULL)
+                    *err = bc_error_new_printf(BC_ERROR_CONFIG_PARSER,
+                        "Section names can't have new lines");
+                break;
+
+            case CONFIG_SECTION_KEY:
+                if (c == '=') {
+                    key = bc_strndup(src + start, current - start);
+                    state = CONFIG_SECTION_VALUE_START;
+                    break;
+                }
+                if (c != '\r' && c != '\n' && !is_last)
+                    break;
+                // key without value, should we support it?
+                if (err != NULL) {
+                    size_t end = is_last && c != '\n' && c != '\r' ? src_len :
+                        current;
+                    key = bc_strndup(src + start, end - start);
+                    *err = bc_error_new_printf(BC_ERROR_CONFIG_PARSER,
+                        "Key without value: %s", key);
+                    free(key);
+                    key = NULL;
+                }
+                break;
+
+            case CONFIG_SECTION_VALUE_START:
+                start = current;
+                state = CONFIG_SECTION_VALUE;
+                break;
+
+            case CONFIG_SECTION_VALUE:
+                if (c == '\r' || c == '\n' || is_last) {
+                    size_t end = is_last && c != '\n' && c != '\r' ? src_len :
+                        current;
+                    value = bc_strndup(src + start, end - start);
+                    bc_trie_insert(section, bc_str_strip(key),
+                        bc_strdup(bc_str_strip(value)));
+                    free(key);
+                    key = NULL;
+                    free(value);
+                    value = NULL;
+                    state = CONFIG_START;
+                    break;
+                }
+                break;
+
+        }
+
+        if (err != NULL && *err != NULL) {
+            bc_config_free(rv);
+            rv = NULL;
+            break;
+        }
+
+        current++;
+    }
+
+    free(section_name);
+    free(key);
+    free(value);
+
+    return rv;
+}
+
+
+static void
+list_keys(const char *key, const char value, bc_slist_t **l)
+{
+    *l = bc_slist_append(*l, bc_strdup(key));
+}
+
+
+char**
+bc_config_list_sections(bc_config_t *config)
+{
+    if (config == NULL)
+        return NULL;
+
+    bc_slist_t *l = NULL;
+    bc_trie_foreach(config->root, (bc_trie_foreach_func_t) list_keys, &l);
+
+    char **rv = bc_malloc(sizeof(char*) * (bc_slist_length(l) + 1));
+
+    unsigned int i = 0;
+    for (bc_slist_t *tmp = l; tmp != NULL; tmp = tmp->next, i++)
+        rv[i] = tmp->data;
+    rv[i] = NULL;
+
+    bc_slist_free(l);
+
+    return rv;
+}
+
+
+char**
+bc_config_list_keys(bc_config_t *config, const char *section)
+{
+    if (config == NULL)
+        return NULL;
+
+    bc_trie_t *s = bc_trie_lookup(config->root, section);
+    if (s == NULL)
+        return NULL;
+
+    bc_slist_t *l = NULL;
+    bc_trie_foreach(s, (bc_trie_foreach_func_t) list_keys, &l);
+
+    char **rv = bc_malloc(sizeof(char*) * (bc_slist_length(l) + 1));
+
+    unsigned int i = 0;
+    for (bc_slist_t *tmp = l; tmp != NULL; tmp = tmp->next, i++)
+        rv[i] = tmp->data;
+    rv[i] = NULL;
+
+    bc_slist_free(l);
+
+    return rv;
+}
+
+
+const char*
+bc_config_get(bc_config_t *config, const char *section, const char *key)
+{
+    if (config == NULL)
+        return NULL;
+
+    bc_trie_t *s = bc_trie_lookup(config->root, section);
+    if (s == NULL)
+        return NULL;
+
+    return bc_trie_lookup(s, key);
+}
+
+
+void
+bc_config_free(bc_config_t *config)
+{
+    if (config == NULL)
+        return;
+    bc_trie_free(config->root);
+    free(config);
+}
diff --git a/src/common/config-parser.h b/src/common/config-parser.h
new file mode 100644
index 0000000..0d30c49
--- /dev/null
+++ b/src/common/config-parser.h
@@ -0,0 +1,26 @@
+/*
+ * blogc: A blog compiler.
+ * Copyright (C) 2014-2016 Rafael G. Martins <rafael@rafaelmartins.eng.br>
+ *
+ * This program can be distributed under the terms of the BSD License.
+ * See the file LICENSE.
+ */
+
+#ifndef _CONFIG_PARSER_H
+#define _CONFIG_PARSER_H
+
+#include "utils.h"
+#include "error.h"
+
+typedef struct {
+    bc_trie_t *root;
+} bc_config_t;
+
+bc_config_t* bc_config_parse(const char *src, size_t src_len, bc_error_t **err);
+char** bc_config_list_sections(bc_config_t *config);
+char** bc_config_list_keys(bc_config_t *config, const char *section);
+const char* bc_config_get(bc_config_t *config, const char *section,
+    const char *key);
+void bc_config_free(bc_config_t *config);
+
+#endif /* _CONFIG_PARSER_H */
diff --git a/src/common/error.h b/src/common/error.h
index 200f9a7..2569538 100644
--- a/src/common/error.h
+++ b/src/common/error.h
@@ -14,6 +14,9 @@
 // error handling is centralized here for the sake of simplicity :/
 typedef enum {
 
+    // errors for src/common
+    BC_ERROR_CONFIG_PARSER = 1,
+
     // errors for src/blogc
     BLOGC_ERROR_SOURCE_PARSER = 100,
     BLOGC_ERROR_TEMPLATE_PARSER,