int AddPageVar(PageVar *varlist, char *cmd) {
char *name = strchr(cmd, ':') + 1;
char *value = strchr(name, ':') + 1;
char *end = strchr(cmd, ']');
if (value - name > sizeof(varlist->name)) {
// Invalid name length
return -1;
}
PageVar *pagevar = GetPageVar(varlist, name, value -1);
if (pagevar != NULL) {
// Special case, variable already exists
if (pagevar->value != NULL) {
free(pagevar->value);
}
} else {
// Add new variable to end of list
pagevar = varlist;
while (pagevar->next != NULL) {
pagevar = pagevar->next;
}
pagevar->next = calloc(sizeof(PageVar), 1);
VerifyPointerOrTerminate(pagevar->next, "New PageVar");
pagevar = pagevar->next;
}
cgc_memcpy(pagevar->name, name, value - 1 - name);
#ifdef PATCHED
if (end - value <= 0) {
return -1;
}
#endif
pagevar->value = calloc(end - value + 1, 1);
VerifyPointerOrTerminate(pagevar->value, "PageVar->value");
cgc_memcpy(pagevar->value, value, end - value);
return 1;
}
// Initializes the server by loading pages into memory
int InitializeTree() {
TreeNode *ptr;
for (int i = 0; i < NUM_INITIAL_PAGES; ++i) {
TreeNode *node = calloc(sizeof(TreeNode), 1);
VerifyPointerOrTerminate(node, "TreeNode during initialization");
strncpy(node->name, InitialInfo[i].name, sizeof(node->name));
node->page_size = strlen(InitialInfo[i].data) + 1;
node->page = calloc(node->page_size, 1);
VerifyPointerOrTerminate(node->page, "node->page during initialization");
memcpy(node->page, InitialInfo[i].data, node->page_size);
if (InsertNodeInTree(node) != 0) {
free(node->page);
free(node);
return -1;
}
}
return 0;
}
int InsertNodeInTree(TreeNode *node) {
if (root == NULL) {
TreeNode *node = calloc(sizeof(TreeNode), 1);
VerifyPointerOrTerminate(node, "root TreeNode during insert");
node->name[0] = '.';
root = node;
}
// Make sure node doesn't exist
if (LookupNode(node->name) != NULL) {
printf("ERROR: node already exists\n");
return -1;
}
// Make sure name isn't blank
if (node->name[0] == '\0') {
printf("ERROR: Name cannot be blank\n");
return -1;
}
// Lookup parent node
char local_name[64];
memcpy(local_name, node->name, sizeof(local_name));
char *last_part = strrchr(local_name, '.');
TreeNode *insert_location = root;
// If no subparts in name, insert as child to root
if (last_part == NULL) {
if (insert_location->child == NULL) {
insert_location->child = node;
} else {
insert_location = insert_location->child;
while (insert_location->peer != NULL) {
insert_location = insert_location->peer;
}
insert_location->peer = node;
}
return 0;
}
// Strip leading portion of name
strncpy(node->name, last_part + 1, sizeof(node->name));
last_part[0] = '\0';
insert_location = LookupNode(local_name);
if (insert_location == NULL) {
printf("ERROR: Parent node doesn't exist: @s\n", local_name);
return -1;
}
if (insert_location->child == NULL) {
insert_location->child = node;
return 0;
} else {
insert_location = insert_location->child;
while (insert_location->peer != NULL) {
insert_location = insert_location->peer;
}
insert_location->peer = node;
return 0;
}
}
// Processes user supplied variable definitions and then serves the requested
// page using those variables.
// Variable definitions are in the same syntax as those scripted in a page
// eg. [var:name:value][var:name2:value2]
int InteractWithPage(char *page, int page_size, char *override_data) {
#ifdef PATCHED
if (override_data == NULL) {
return ServePageWithOverride(page, page_size, NULL);
}
#endif
PageVar *override_list = calloc(sizeof(PageVar), 1);
VerifyPointerOrTerminate(override_list, "Override_list initialization");
// Process override variable definitions
while(*override_data != '\0' && *override_data != ']') {
// Check for start of var definition
if (*override_data != '[') { break; }
// Process var definition
AddPageVar(override_list, override_data);
// Locate end of var definition
char *end_of_var = strchr(override_data, ']');
if (end_of_var == NULL) { break; }
// Step over var definition
override_data = end_of_var + 1;
}
// Serve page with overridden variables
return ServePageWithOverride(page, page_size, override_list);
}
// Serves a page by interpreting command codes, processing script commands,
// and handling variable substitution. Any variables provided in the override_list
// will take precedence over variables of the same name defined in the page.
int ServePageWithOverride(char *page, int page_size, PageVar *override_list) {
// Initialize varlist
PageVar *varlist = calloc(sizeof(PageVar), 1);
VerifyPointerOrTerminate(varlist, "VarList initialization");
in_a_box = 0;
cgc_memset(line, '\0', sizeof(line));
line_length = 0;
#ifdef PATCHED
if (page == NULL) {
goto error;
}
#endif
while ((*page != '\0')&&(page < page + page_size)) {
if (*page == '~') {
// Command character, process command
page++;
switch (*page) {
case 't': {
for (int i=0; i<4; i++) {
OutputChar(' ');
}
break;
}
case 'n': {
FlushOutput();
break;
}
case '[': {
OutputChar('[');
break;
}
case ']': {
OutputChar(']');
break;
}
case '~': {
OutputChar('~');
break;
}
case '#': {
OutputChar('#');
break;
}
default: {
printf("ERROR: Invalid control code\n");
goto error;
}
}
page++;
} else if (*page == '[') {
// Script tag, find closing tag and process script
char *close = ++page;
while (*close != ']' && *close != '\0') close++;
if (*close == '\0') {
goto error;
}
// Process script commands
if (strncmp(page, "line", cgc_strlen("line")) == 0) {
page += cgc_strlen("line");
if (*page != ':') {
goto error;
}
char c = *(++page);
if (*(++page) != ':') {
goto error;
}
int length = atoi(++page);
for (int i = 0; i < length; i++) {
OutputChar(c);
}
page = close + 1;
} else if (strncmp(page, "var", cgc_strlen("var")) == 0) {
AddPageVar(varlist, page);
page = close + 1;
} else if (strncmp(page, "box", cgc_strlen("box")) == 0) {
in_a_box = 1;
FlushOutput();
for (int i = 0; i < 80; i++) {
putc('*');
}
printf("\n");
page += 4;
}
} else if (*page == ']') {
page++;
if (in_a_box) {
in_a_box = 0;
FlushOutput();
for (int i = 0; i < 80; i++) {
putc('*');
}
printf("\n");
} else {
goto error;
}
} else if (*page == '#') {
// Variable substitution
char *end = ++page;
while (*end != '\0' && *end != '#') { end++; }
if (*end != '#') {
goto error;
}
PageVar *var = NULL;
// Check for overridden variables
if (override_list != NULL) {
var = GetPageVar(override_list, page, end);
}
// Fall back to default values if override doesn't exist
if (var == NULL) {
var = GetPageVar(varlist, page, end);
}
// If a value has been found, output it
if (var != NULL) {
OutputStr(var->value);
}
page = end + 1;
} else {
// Normal character, send to output
OutputChar(*page);
page++;
}
}
if (line_length != 0) {
FlushOutput();
}
DestroyVarList(varlist);
DestroyVarList(override_list);
return 0;
error:
printf("ERROR: Invalid syntax\n");
DestroyVarList(varlist);
DestroyVarList(override_list);
return -1;
}
