Support parsing streams from config file. Also support multiple streams (includes...

[cubemap] / parse.cpp

diff --git a/parse.cpp b/parse.cpp
new file mode 100644 (file)
index 0000000..0747afb
--- /dev/null
+++ b/parse.cpp
@@ -0,0 +1,143 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <assert.h>
+#include <vector>
+#include <string>
+
+#include "parse.h"
+
+using namespace std;
+
+vector<string> split_tokens(const string &line)
+{
+       vector<string> ret;
+       string current_token;
+
+       for (size_t i = 0; i < line.size(); ++i) {
+               if (isspace(line[i])) {
+                       if (!current_token.empty()) {
+                               ret.push_back(current_token);
+                       }
+                       current_token.clear();
+               } else {
+                       current_token.push_back(line[i]);
+               }
+       }
+       if (!current_token.empty()) {
+               ret.push_back(current_token);
+       }
+       return ret;
+}
+
+vector<string> split_lines(const string &str)
+{
+       vector<string> ret;
+       string current_line;
+
+       for (size_t i = 0; i < str.size(); ++i) {
+               // Skip \r if followed by an \n.
+               if (str[i] == '\r' && i < str.size() - 1 && str[i + 1] == '\n') {
+                       continue;
+               }
+
+               // End of the current line?
+               if (str[i] == '\n') {
+                       if (!current_line.empty()) {
+                               ret.push_back(current_line);
+                       }
+                       current_line.clear();
+               } else {
+                       current_line.push_back(str[i]);
+               }
+       }
+       if (!current_line.empty()) {
+               ret.push_back(current_line);
+       }
+       return ret;
+}
+
+vector<ConfigLine> parse_config(const string &filename)
+{
+       vector<ConfigLine> ret;
+
+       FILE *fp = fopen(filename.c_str(), "r");
+       if (fp == NULL) {
+               perror(filename.c_str());
+               exit(1);
+       }
+
+       char buf[4096];
+       while (!feof(fp)) {
+               if (fgets(buf, sizeof(buf), fp) == NULL) {
+                       break;
+               }
+
+               // Chop off the string at the first #, \r or \n.
+               buf[strcspn(buf, "#\r\n")] = 0;
+
+               // Remove all whitespace from the end of the string.
+               size_t len = strlen(buf);
+               while (len > 0 && isspace(buf[len - 1])) {
+                       buf[--len] = 0;
+               }
+
+               // If the line is now all blank, ignore it.
+               if (len == 0) {
+                       continue;
+               }
+
+               vector<string> tokens = split_tokens(buf);
+               assert(!tokens.empty());
+               
+               ConfigLine line;
+               line.keyword = tokens[0];
+
+               for (size_t i = 1; i < tokens.size(); ++i) {
+                       // foo=bar is a parameter; anything else is an argument.
+                       size_t equals_pos = tokens[i].find_first_of('=');
+                       if (equals_pos == string::npos) {
+                               line.arguments.push_back(tokens[i]);
+                       } else {
+                               string key = tokens[i].substr(0, equals_pos);
+                               string value = tokens[i].substr(equals_pos + 1, string::npos);
+                               line.parameters.insert(make_pair(key, value));
+                       }
+               }
+
+               ret.push_back(line);
+       }
+
+       fclose(fp);
+       return ret;
+}
+
+int fetch_config_int(const vector<ConfigLine> &config, const string &keyword, int min_limit, int max_limit)
+{
+       bool value_found = false;
+       int value = -1;
+       for (unsigned i = 0; i < config.size(); ++i) {
+               if (config[i].keyword != keyword) {
+                       continue;
+               }
+               if (config[i].parameters.size() > 0 ||
+                   config[i].arguments.size() != 1) {
+                       fprintf(stderr, "ERROR: '%s' takes one argument and no parameters\n", keyword.c_str());
+                       exit(1);
+               }
+               value_found = true;
+               value = atoi(config[i].arguments[0].c_str());  // TODO: verify int validity.
+       }
+       if (!value_found) {
+               fprintf(stderr, "ERROR: Missing '%s' statement in config file.\n",
+                       keyword.c_str());
+               exit(1);
+       }
+       if (value < min_limit || value > max_limit) {
+               fprintf(stderr, "ERROR: '%s' is set to %d, must be in [%d,%d]\n",
+                       keyword.c_str(), value, min_limit, max_limit);
+               exit(1);
+       }
+       return value;
+}