Table: Renaming callbacks to a formatter

I wish to demonstrate a clear split between the front-end
and formatter back-end.

diff --git a/ucw/table-test.c b/ucw/table-test.c
index ee019541a5e65b337dafe69de300fadbbb7e865e..b033720838e5d83964660057600b85051e82e4c5 100644 (file)
--- a/ucw/table-test.c
+++ b/ucw/table-test.c
@@ -117,23 +117,23 @@ static void process_command_line_opts(char *argv[], struct table *tbl)
   GARY_FREE(cli_table_opts);
 }
 
-static int user_defined_option(struct table *tbl UNUSED, const char *key, const char *value)
+static bool user_defined_option(struct table *tbl UNUSED, const char *key, const char *value, const char **err UNUSED)
 {
   if(value == NULL && strcmp(key, "novaluekey") == 0) {
     printf("setting key: %s; value: (null)\n", key);
-    return 0;
+    return 1;
   }
   if(value != NULL && strcmp(value, "value") == 0 &&
      key != NULL && strcmp(key, "valuekey") == 0) {
     printf("setting key: %s; value: %s\n", key, value);
-    return 0;
+    return 1;
   }
-  return 1;
+  return 0;
 }
 
 static void test_option_parser(struct table *tbl)
 {
-  tbl->callbacks->process_option = user_defined_option;
+  tbl->formatter->process_option = user_defined_option;
   const char *rv = table_set_option(tbl, "invalid:option");
   if(rv) printf("Tableprinter option parser returned error: \"%s\".\n", rv);
 

diff --git a/ucw/table.c b/ucw/table.c
index fc2a25ea2de766b59122965483f79d886fe48a92..352cf936ea65ff585b0331d44a03f8f775b3b475 100644 (file)
--- a/ucw/table.c
+++ b/ucw/table.c
@@ -36,9 +36,8 @@ void table_init(struct table *tbl, struct fastbuf *out)
 
   tbl->column_count = col_count;
 
-  // FIXME: Why? Better check if tbl->callbacks is NULL.
-  if(tbl->callbacks->row_output_func == NULL && tbl->callbacks->table_start_callback == NULL && tbl->callbacks->table_end_callback == NULL) {
-    tbl->callbacks = &table_fmt_human_readable;
+  if(!tbl->formatter) {
+    tbl->formatter = &table_fmt_human_readable;
   }
 
   tbl->print_header = 1; // by default, print header
@@ -70,7 +69,7 @@ void table_start(struct table *tbl)
 
   if(tbl->column_order == NULL) table_make_default_column_order(tbl);
 
-  if(tbl->callbacks->table_start_callback != NULL) tbl->callbacks->table_start_callback(tbl);
+  if(tbl->formatter->table_start != NULL) tbl->formatter->table_start(tbl);
   if(tbl->cols_to_output == 0) {
     // FIXME: Why?
     die("Table should output at least one column.");
@@ -90,14 +89,14 @@ void table_end(struct table *tbl)
 
   mp_restore(tbl->pool, &tbl->pool_state);
 
-  if(tbl->callbacks->table_end_callback) tbl->callbacks->table_end_callback(tbl);
+  if(tbl->formatter->table_end) tbl->formatter->table_end(tbl);
 }
 
 /*** Configuration ***/
 
-void table_set_output_callbacks(struct table *tbl, struct table_output_callbacks *callbacks)
+void table_set_formatter(struct table *tbl, struct table_formatter *fmt)
 {
-  tbl->callbacks = callbacks;
+  tbl->formatter = fmt;
 }
 
 int table_get_col_idx(struct table *tbl, const char *col_name)
@@ -112,6 +111,7 @@ const char * table_get_col_list(struct table *tbl)
 {
   if(tbl->column_count == 0) return NULL;
 
+  // FIXME: This does not work! The start of the string may be reallocated later.
   char *tmp = mp_printf(tbl->pool, "%s", tbl->columns[0].name);
 
   for(int i = 1; i < tbl->column_count; i++) {
@@ -311,11 +311,8 @@ void table_append_printf(struct table *tbl, const char *fmt, ...)
 
 void table_end_row(struct table *tbl)
 {
-  if(tbl->callbacks->row_output_func) {
-    tbl->callbacks->row_output_func(tbl);
-  } else {
-    die("Tableprinter: invalid parameter, struct table does not have filled row_output_func");
-  }
+  ASSERT(tbl->formatter->row_output);
+  tbl->formatter->row_output(tbl);
   memset(tbl->col_str_ptrs, 0, sizeof(char *) * tbl->column_count);
   mp_restore(tbl->pool, &tbl->pool_state);
   tbl->last_printed_col = -1;
@@ -340,29 +337,18 @@ void table_col_fbend(struct table *tbl)
 
 /*** Option parsing ***/
 
-static int get_colon(char *str)
-{
-  int l = strlen(str);
-  for(int i = 0; i < l; i++) {
-    if(str[i] == ':') return i;
-  }
-  return -1;
-}
-
-static const char *table_set_option2(struct table *tbl, const char *key, const char *value)
+const char *table_set_option_value(struct table *tbl, const char *key, const char *value)
 {
+  // Options with no value
   if(value == NULL || (value != NULL && strlen(value) == 0)) {
     if(strcmp(key, "noheader") == 0) {
       tbl->print_header = 0;
       return NULL;
-    } else {
-      int rv = 1;
-      if(tbl->callbacks && tbl->callbacks->process_option) rv = tbl->callbacks->process_option(tbl, key, value);
-      if(rv) {
-        return mp_printf(tbl->pool, "Tableprinter: invalid option: '%s'.", key);
-      }
     }
-  } else {
+  }
+
+  // Options with a value
+  if(value) {
     if(strcmp(key, "header") == 0) {
       // FIXME: Check syntax of value.
       //tbl->print_header = strtol(value, NULL, 10); //atoi(value);
@@ -382,8 +368,8 @@ static const char *table_set_option2(struct table *tbl, const char *key, const c
       }
       return NULL;
     } else if(strcmp(key, "fmt") == 0) {
-      if(strcmp(value, "human") == 0) table_set_output_callbacks(tbl, &table_fmt_human_readable);
-      else if(strcmp(value, "machine") == 0) table_set_output_callbacks(tbl, &table_fmt_machine_readable);
+      if(strcmp(value, "human") == 0) table_set_formatter(tbl, &table_fmt_human_readable);
+      else if(strcmp(value, "machine") == 0) table_set_formatter(tbl, &table_fmt_machine_readable);
       else {
         return "Tableprinter: invalid argument to output-type option.";
       }
@@ -392,42 +378,45 @@ static const char *table_set_option2(struct table *tbl, const char *key, const c
       char * d = mp_printf(tbl->pool, "%s", value);
       tbl->col_delimiter = d;
       return NULL;
-    } else {
-      int rv = 1;
-      if(tbl->callbacks && tbl->callbacks->process_option) rv = tbl->callbacks->process_option(tbl, key, value);
-      if(rv) {
-        return mp_printf(tbl->pool, "Tableprinter: invalid option: '%s:%s'.", key, value);
-      }
     }
   }
-  return NULL;
+
+  // Formatter options
+  if(tbl->formatter && tbl->formatter->process_option) {
+    const char *err = NULL;
+    if (tbl->formatter->process_option(tbl, key, value, &err)) {
+      return err;
+    }
+  }
+
+  // Unrecognized option
+  return mp_printf(tbl->pool, "Tableprinter: invalid option: '%s%s%s'.", key, (value ? ":" : ""), (value ? : ""));
 }
 
 const char *table_set_option(struct table *tbl, const char *opt)
 {
-  char *opt_dup = stk_strdup(opt);
-  int colidx = get_colon(opt_dup);
-  if(colidx > 0) opt_dup[colidx] = 0;
-  char *key = opt_dup;
-  char *value = NULL;
-  if(colidx > 0) value = opt_dup + colidx + 1;
-  return table_set_option2(tbl, key, value);
+  char *key = stk_strdup(opt);
+  char *value = strchr(key, ':');
+  if(value) {
+    *value++ = 0;
+  }
+  return table_set_option_value(tbl, key, value);
 }
 
 const char *table_set_gary_options(struct table *tbl, char **gary_table_opts)
 {
   for (uint i = 0; i < GARY_SIZE(gary_table_opts); i++) {
     const char *rv = table_set_option(tbl, gary_table_opts[i]);
-    if (rv != NULL) {
+    if(rv != NULL) {
       return rv;
     }
   }
   return NULL;
 }
 
-/*** Default formatter for human-readble output ***/
+/*** Default formatter for human-readable output ***/
 
-static int table_oneline_human_readable(struct table *tbl)
+static void table_row_human_readable(struct table *tbl)
 {
   uint col = tbl->column_order[0];
   int col_width = tbl->columns[col].width;
@@ -440,7 +429,6 @@ static int table_oneline_human_readable(struct table *tbl)
   }
 
   bputc(tbl->out, '\n');
-  return 0;
 }
 
 static void table_write_header(struct table *tbl)
@@ -457,7 +445,7 @@ static void table_write_header(struct table *tbl)
   bputc(tbl->out, '\n');
 }
 
-static int table_start_human_readable(struct table *tbl)
+static void table_start_human_readable(struct table *tbl)
 {
   if(tbl->col_delimiter == NULL) {
     tbl->col_delimiter = " ";
@@ -471,23 +459,16 @@ static int table_start_human_readable(struct table *tbl)
     tbl->print_header = 0;
     table_write_header(tbl);
   }
-  return 0;
-}
-
-static int table_end_human_readable(struct table *tbl UNUSED)
-{
-  return 0;
 }
 
-struct table_output_callbacks table_fmt_human_readable = {
-  .row_output_func = table_oneline_human_readable,
-  .table_start_callback = table_start_human_readable,
-  .table_end_callback = table_end_human_readable,
+struct table_formatter table_fmt_human_readable = {
+  .row_output = table_row_human_readable,
+  .table_start = table_start_human_readable,
 };
 
 /*** Default formatter for machine-readable output ***/
 
-static int table_oneline_machine_readable(struct table *tbl)
+static void table_row_machine_readable(struct table *tbl)
 {
   uint col = tbl->column_order[0];
   bputs(tbl->out, tbl->col_str_ptrs[col]);
@@ -498,10 +479,9 @@ static int table_oneline_machine_readable(struct table *tbl)
   }
 
   bputc(tbl->out, '\n');
-  return 0;
 }
 
-static int table_start_machine_readable(struct table *tbl)
+static void table_start_machine_readable(struct table *tbl)
 {
   if(tbl->col_delimiter == NULL) {
     tbl->col_delimiter = ";";
@@ -525,18 +505,11 @@ static int table_start_machine_readable(struct table *tbl)
     }
     bputc(tbl->out, '\n');
   }
-  return 0;
-}
-
-static int table_end_machine_readable(struct table *tbl UNUSED)
-{
-  return 0;
 }
 
-struct table_output_callbacks table_fmt_machine_readable = {
-  .row_output_func = table_oneline_machine_readable,
-  .table_start_callback = table_start_machine_readable,
-  .table_end_callback = table_end_machine_readable,
+struct table_formatter table_fmt_machine_readable = {
+  .row_output = table_row_machine_readable,
+  .table_start = table_start_machine_readable,
 };
 
 /*** Tests ***/

diff --git a/ucw/table.h b/ucw/table.h
index b1c5423884119863c2e29c0cd609b7f77e22aca9..ad2173d4a9e965d99b9feedcb7120492bd958ef9 100644 (file)
--- a/ucw/table.h
+++ b/ucw/table.h
@@ -47,8 +47,8 @@ enum column_type {
 #define TBL_COL_DELIMITER(_delimiter_) .col_delimiter = _delimiter_
 #define TBL_APPEND_DELIMITER(_delimiter_) .append_delimiter = _delimiter_
 
-#define TBL_OUTPUT_HUMAN_READABLE     .callbacks = &table_fmt_human_readable
-#define TBL_OUTPUT_MACHINE_READABLE   .callbacks = &table_fmt_machine_readable
+#define TBL_OUTPUT_HUMAN_READABLE     .formatter = &table_fmt_human_readable
+#define TBL_OUTPUT_MACHINE_READABLE   .formatter = &table_fmt_machine_readable
 
 /***
  * [[ Usage ]]
@@ -133,15 +133,6 @@ struct table_column {
   enum column_type type;       // Type of the cells in the column
 };
 
-struct table_output_callbacks {
-  int (*row_output_func)(struct table *tbl);       // [*] Function that outputs one row
-  int (*table_start_callback)(struct table *tbl);  // [*] table_start callback
-  int (*table_end_callback)(struct table *tbl);    // [*] table_end callback
-       // FIXME: Int -> void?
-  int (*process_option)(struct table *tbl, const char *key, const char *value);
-       // FIXME: Shouldn't it be possible to return also a custom error string? For example in an optionally writeable `const char **' argument.
-};
-
 /** The definition of a table. Contains column definitions plus internal data. */
 struct table {
   struct table_column *columns;                // [*] Definition of columns
@@ -167,7 +158,7 @@ struct table {
   int col_out;                         // Index of the column that is currently printed using fb_col_out
 
   // Back-end used for table formatting and its private data
-  struct table_output_callbacks *callbacks;
+  struct table_formatter *formatter;
   void *data;
 };
 
@@ -256,10 +247,22 @@ struct fastbuf *table_col_fbstart(struct table *tbl, int col);
 void table_col_fbend(struct table *tbl);
 
 /**
- * Sets the callbacks in @tbl. The callbacks are stored the arg @callbacks.
+ * Sets table formatter for @tbl.
  **/
-void table_set_output_callbacks(struct table *tbl, struct table_output_callbacks *callbacks);
+void table_set_formatter(struct table *tbl, struct table_formatter *fmt);
+
+/** Definition of a formatter back-end. **/
+struct table_formatter {
+  void (*row_output)(struct table *tbl);       // [*] Function that outputs one row
+  void (*table_start)(struct table *tbl);      // [*] table_start callback (optional)
+  void (*table_end)(struct table *tbl);                // [*] table_end callback (optional)
+  bool (*process_option)(struct table *tbl, const char *key, const char *value, const char **err);
+       // [*] Process table option and possibly return an error message (optional)
+};
 
+// Standard formatters
+extern struct table_formatter table_fmt_human_readable;
+extern struct table_formatter table_fmt_machine_readable;
 
 /**
  * Process the table one option and sets the values in @tbl according to the command-line parameters.
@@ -275,12 +278,9 @@ void table_set_output_callbacks(struct table *tbl, struct table_output_callbacks
  * Returns NULL on success or an error string otherwise.
  **/
 const char *table_set_option(struct table *tbl, const char *opt);
+const char *table_set_option_value(struct table *tbl, const char *key, const char *value);
 const char *table_set_gary_options(struct table *tbl, char **gary_table_opts);
 
-// Standard formatters
-extern struct table_output_callbacks table_fmt_human_readable;
-extern struct table_output_callbacks table_fmt_machine_readable;
-
 #define TABLE_SET_COL_PROTO(_name_, _type_) void table_set_##_name_(struct table *tbl, int col, _type_ val);\
   void table_set_##_name_##_name(struct table *tbl, const char *col_name, _type_ val);\
   void table_set_##_name_##_fmt(struct table *tbl, int col, const char *fmt, _type_ val) FORMAT_CHECK(printf, 3, 0);