csv parser

1 files changed, 152 insertions, 0 deletions

diff --git a/src/csv_parser.c b/src/csv_parser.c
new file mode 100644
index 0000000..29f0529
--- /dev/null
+++ b/src/csv_parser.c
@@ -0,0 +1,152 @@
+/**
+ * Copyright (C) 2013 Tadas Vilkeliskis <vilkeliskis.t@gmail.com>
+ *
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <assert.h>
+#include <stdlib.h>
+#include <csv_parser.h>
+
+
+void csv_parser_init(csv_parser_t *parser)
+{
+    assert(parser);
+    parser->state = csvps_line_start;
+    parser->row = -1;
+    parser->col = -1;
+    parser->nread = 0;
+    parser->data = NULL;
+}
+
+
+size_t csv_parser_execute(csv_parser_t *parser,
+                          const csv_parser_settings_t *settings,
+                          const char *data,
+                          size_t data_len)
+{
+    assert(parser);
+    assert(settings);
+    assert(data);
+
+    const char *cursor = data;
+    const char *field_value = NULL;
+    const char *data_end = data + data_len;
+    int r;
+    parser->nread = 0;
+
+    if (data_len < 1) {
+        return 0;
+    }
+
+    while (cursor < data_end) {
+        char ch = *cursor;
+        switch (parser->state) {
+            case csvps_line_start:
+                field_value = NULL;
+                parser->row += 1;
+                parser->col = -1;
+                if (ch == '\r' || ch == '\n') {
+                    parser->state = csvps_line_end_begin;
+                } else {
+                    parser->state = csvps_field_start;
+                }
+                break;
+            case csvps_field_start:
+                parser->col += 1;
+                parser->state = csvps_field_value;
+                field_value = cursor;
+                break;
+            case csvps_field_value:
+                if (ch == settings->delimiter) {
+                    parser->state = csvps_field_end;
+                } else if (ch == '\r' || ch == '\n') {
+                    parser->state = csvps_line_end_begin;
+                } else {
+                    // If we previously been in csvps_field_value state
+                    // and field_value is not set, set it right away.
+                    // This can happen when we execute parser multiple
+                    // times in the value state.
+                    if (field_value == NULL) {
+                        field_value = cursor;
+                    }
+
+                    cursor++;
+                    if (cursor == data_end) {
+                        if (settings->field_cb && field_value) {
+                            r = settings->field_cb(parser,
+                                                   field_value,
+                                                   cursor - field_value,
+                                                   parser->row,
+                                                   parser->col);
+                            if (r) {
+                                return parser->nread;
+                            }
+                        }
+                    }
+                    parser->nread++;
+                }
+                break;
+            case csvps_field_end:
+                // callback
+                if (settings->field_cb && field_value) {
+                    r = settings->field_cb(parser,
+                                           field_value,
+                                           cursor - field_value,
+                                           parser->row,
+                                           parser->col);
+                    if (r) {
+                        return parser->nread;
+                    }
+                }
+
+                parser->state = csvps_field_start;
+                cursor++;
+                parser->nread++;
+                break;
+            case csvps_line_end_begin:
+                // callback
+                if (settings->field_cb && field_value) {
+                    r = settings->field_cb(parser,
+                                           field_value,
+                                           cursor - field_value,
+                                           parser->row,
+                                           parser->col);
+                    if (r) {
+                        return parser->nread;
+                    }
+                }
+                parser->state = csvps_line_end;
+                break;
+            case csvps_line_end:
+                if (ch == '\r' || ch == '\n') {
+                    cursor++;
+                    parser->nread++;
+                } else {
+                    parser->state = csvps_line_start;
+                }
+                break;
+            default:
+                assert(0 && "invalid parser state");
+                break;
+        }
+    }
+
+    return parser->nread;
+}