--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/c/urweb.c	Sun Aug 31 08:35:00 2008 -0400
@@ -0,0 +1,555 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <setjmp.h>
+#include <stdarg.h>
+
+#include "types.h"
+
+lw_unit lw_unit_v = {};
+
+#define ERROR_BUF_LEN 1024
+
+struct lw_context {
+  char *page, *page_front, *page_back;
+  char *heap, *heap_front, *heap_back;
+  char **inputs;
+
+  jmp_buf jmp_buf;
+
+  char error_message[ERROR_BUF_LEN];
+};
+
+extern int lw_inputs_len;
+
+lw_context lw_init(size_t page_len, size_t heap_len) {
+  lw_context ctx = malloc(sizeof(struct lw_context));
+
+  ctx->page_front = ctx->page = malloc(page_len);
+  ctx->page_back = ctx->page_front + page_len;
+
+  ctx->heap_front = ctx->heap = malloc(heap_len);
+  ctx->heap_back = ctx->heap_front + heap_len;
+
+  ctx->inputs = calloc(lw_inputs_len, sizeof(char *));
+
+  ctx->error_message[0] = 0;
+
+  return ctx;
+}
+
+void lw_free(lw_context ctx) {
+  free(ctx->page);
+  free(ctx->heap);
+  free(ctx->inputs);
+  free(ctx);
+}
+
+void lw_reset_keep_request(lw_context ctx) {
+  ctx->page_front = ctx->page;
+  ctx->heap_front = ctx->heap;
+
+  ctx->error_message[0] = 0;
+}
+
+void lw_reset_keep_error_message(lw_context ctx) {
+  ctx->page_front = ctx->page;
+  ctx->heap_front = ctx->heap;
+}
+
+void lw_reset(lw_context ctx) {
+  lw_reset_keep_request(ctx);
+  memset(ctx->inputs, 0, lw_inputs_len * sizeof(char *));
+}
+
+void lw_handle(lw_context, char *);
+
+failure_kind lw_begin(lw_context ctx, char *path) {
+  int r = setjmp(ctx->jmp_buf);
+
+  if (r == 0)
+    lw_handle(ctx, path);
+
+  return r;
+}
+
+void lw_error(lw_context ctx, failure_kind fk, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+
+  vsnprintf(ctx->error_message, ERROR_BUF_LEN, fmt, ap);
+
+  longjmp(ctx->jmp_buf, fk);
+}
+
+char *lw_error_message(lw_context ctx) {
+  return ctx->error_message;
+}
+
+int lw_input_num(char*);
+
+void lw_set_input(lw_context ctx, char *name, char *value) {
+  int n = lw_input_num(name);
+
+  if (n < 0)
+    lw_error(ctx, FATAL, "Bad input name %s", name);
+
+  if (n >= lw_inputs_len)
+    lw_error(ctx, FATAL, "For input name %s, index %d is out of range", name, n);
+
+  ctx->inputs[n] = value;
+
+  printf("[%d] %s = %s\n", n, name, value);
+}
+
+char *lw_get_input(lw_context ctx, int n) {
+  if (n < 0)
+    lw_error(ctx, FATAL, "Negative input index %d", n);
+  if (n >= lw_inputs_len)
+    lw_error(ctx, FATAL, "Out-of-bounds input index %d", n);
+  printf("[%d] = %s\n", n, ctx->inputs[n]);
+  return ctx->inputs[n];
+}
+
+char *lw_get_optional_input(lw_context ctx, int n) {
+  if (n < 0)
+    lw_error(ctx, FATAL, "Negative input index %d", n);
+  if (n >= lw_inputs_len)
+    lw_error(ctx, FATAL, "Out-of-bounds input index %d", n);
+  printf("[%d] = %s\n", n, ctx->inputs[n]);
+  return (ctx->inputs[n] == NULL ? "" : ctx->inputs[n]);
+}
+
+static void lw_check_heap(lw_context ctx, size_t extra) {
+  if (ctx->heap_back - ctx->heap_front < extra) {
+    size_t desired = ctx->heap_back - ctx->heap_front + extra, next;
+    char *new_heap;
+
+    for (next = ctx->heap_back - ctx->heap_front; next < desired; next *= 2);
+
+    new_heap = realloc(ctx->heap, next);
+    ctx->heap_front = new_heap;
+    ctx->heap_back = new_heap + next;
+
+    if (new_heap != ctx->heap) {
+      ctx->heap = new_heap;
+      lw_error(ctx, UNLIMITED_RETRY, "Couldn't allocate new heap chunk contiguously");
+    }
+
+    ctx->heap = new_heap;
+  }
+}
+
+void *lw_malloc(lw_context ctx, size_t len) {
+  void *result;
+
+  lw_check_heap(ctx, len);
+
+  result = ctx->heap_front;
+  ctx->heap_front += len;
+  return result;
+}
+
+int lw_really_send(int sock, const void *buf, ssize_t len) {
+  while (len > 0) {
+    ssize_t n = send(sock, buf, len, 0);
+
+    if (n < 0)
+      return n;
+
+    buf += n;
+    len -= n;
+  }
+
+  return 0;
+}
+
+int lw_send(lw_context ctx, int sock) {
+  return lw_really_send(sock, ctx->page, ctx->page_front - ctx->page);
+}
+
+static void lw_check(lw_context ctx, size_t extra) {
+  size_t desired = ctx->page_back - ctx->page_front + extra, next;
+  char *new_page;
+
+  for (next = ctx->page_back - ctx->page_front; next < desired; next *= 2);
+
+  new_page = realloc(ctx->page, next);
+  ctx->page_front = new_page + (ctx->page_front - ctx->page);
+  ctx->page_back = new_page + (ctx->page_back - ctx->page);
+  ctx->page = new_page;
+}
+
+static void lw_writec_unsafe(lw_context ctx, char c) {
+  *(ctx->page_front)++ = c;
+}
+
+void lw_writec(lw_context ctx, char c) {
+  lw_check(ctx, 1);
+  lw_writec_unsafe(ctx, c);
+}
+
+static void lw_write_unsafe(lw_context ctx, const char* s) {
+  int len = strlen(s);
+  memcpy(ctx->page_front, s, len);
+  ctx->page_front += len;
+}
+
+void lw_write(lw_context ctx, const char* s) {
+  lw_check(ctx, strlen(s) + 1);
+  lw_write_unsafe(ctx, s);
+  *ctx->page_front = 0;
+}
+
+
+#define INTS_MAX 50
+#define FLOATS_MAX 100
+
+char *lw_Basis_attrifyInt(lw_context ctx, lw_Basis_int n) {
+  char *result;
+  int len;
+  lw_check_heap(ctx, INTS_MAX);
+  result = ctx->heap_front;
+  sprintf(result, "%d%n", n, &len);
+  ctx->heap_front += len+1;
+  return result;
+}
+
+char *lw_Basis_attrifyFloat(lw_context ctx, lw_Basis_float n) {
+  char *result;
+  int len;
+  lw_check_heap(ctx, FLOATS_MAX);
+  result = ctx->heap_front;
+  sprintf(result, "%g%n", n, &len);
+  ctx->heap_front += len+1;
+  return result;
+}
+
+char *lw_Basis_attrifyString(lw_context ctx, lw_Basis_string s) {
+  int len = strlen(s);
+  char *result, *p;
+  lw_check_heap(ctx, len * 6 + 1);
+
+  result = p = ctx->heap_front;
+
+  for (; *s; s++) {
+    char c = *s;
+
+    if (c == '"') {
+      strcpy(p, "&quot;");
+      p += 6;
+    } else if (c == '&') {
+      strcpy(p, "&amp;");
+      p += 5;
+    }
+    else if (isprint(c))
+      *p++ = c;
+    else {
+      int len2;
+      sprintf(p, "&#%d;%n", c, &len2);
+      p += len2;
+    }
+  }
+
+  *p++ = 0;
+  ctx->heap_front = p;
+  return result;
+}
+
+static void lw_Basis_attrifyInt_w_unsafe(lw_context ctx, lw_Basis_int n) {
+  int len;
+
+  sprintf(ctx->page_front, "%d%n", n, &len);
+  ctx->page_front += len;
+}
+
+void lw_Basis_attrifyInt_w(lw_context ctx, lw_Basis_int n) {
+  lw_check(ctx, INTS_MAX);
+  lw_Basis_attrifyInt_w_unsafe(ctx, n);
+}
+
+void lw_Basis_attrifyFloat_w(lw_context ctx, lw_Basis_float n) {
+  int len;
+
+  lw_check(ctx, FLOATS_MAX);
+  sprintf(ctx->page_front, "%g%n", n, &len);
+  ctx->page_front += len;
+}
+
+void lw_Basis_attrifyString_w(lw_context ctx, lw_Basis_string s) {
+  lw_check(ctx, strlen(s) * 6);
+
+  for (; *s; s++) {
+    char c = *s;
+
+    if (c == '"')
+      lw_write_unsafe(ctx, "&quot;");
+    else if (c == '&')
+      lw_write_unsafe(ctx, "&amp;");
+    else if (isprint(c))
+      lw_writec_unsafe(ctx, c);
+    else {
+      lw_write_unsafe(ctx, "&#");
+      lw_Basis_attrifyInt_w_unsafe(ctx, c);
+      lw_writec_unsafe(ctx, ';');
+    }
+  }
+}
+
+
+char *lw_Basis_urlifyInt(lw_context ctx, lw_Basis_int n) {
+  int len;
+  char *r;
+
+  lw_check_heap(ctx, INTS_MAX);
+  r = ctx->heap_front;
+  sprintf(r, "%d%n", n, &len);
+  ctx->heap_front += len+1;
+  return r;
+}
+
+char *lw_Basis_urlifyFloat(lw_context ctx, lw_Basis_float n) {
+  int len;
+  char *r;
+
+  lw_check_heap(ctx, FLOATS_MAX);
+  r = ctx->heap_front;
+  sprintf(r, "%g%n", n, &len);
+  ctx->heap_front += len+1;
+  return r;
+}
+
+char *lw_Basis_urlifyString(lw_context ctx, lw_Basis_string s) {
+  char *r, *p;
+
+  lw_check_heap(ctx, strlen(s) * 3 + 1);
+
+  for (r = p = ctx->heap_front; *s; s++) {
+    char c = *s;
+
+    if (c == ' ')
+      *p++ = '+';
+    else if (isalnum(c))
+      *p++ = c;
+    else {
+      sprintf(p, "%%%02X", c);
+      p += 3;
+    }
+  }
+
+  *p++ = 0;
+  ctx->heap_front = p;
+  return r;
+}
+
+char *lw_Basis_urlifyBool(lw_context ctx, lw_Basis_bool b) {
+  if (b == lw_Basis_False)
+    return "0";
+  else
+    return "1";
+}
+
+static void lw_Basis_urlifyInt_w_unsafe(lw_context ctx, lw_Basis_int n) {
+  int len;
+
+  sprintf(ctx->page_front, "%d%n", n, &len);
+  ctx->page_front += len;
+}
+
+void lw_Basis_urlifyInt_w(lw_context ctx, lw_Basis_int n) {
+  lw_check(ctx, INTS_MAX);
+  lw_Basis_urlifyInt_w_unsafe(ctx, n);
+}
+
+void lw_Basis_urlifyFloat_w(lw_context ctx, lw_Basis_float n) {
+  int len;
+
+  lw_check(ctx, FLOATS_MAX);
+  sprintf(ctx->page_front, "%g%n", n, &len);
+  ctx->page_front += len;
+}
+
+void lw_Basis_urlifyString_w(lw_context ctx, lw_Basis_string s) {
+  lw_check(ctx, strlen(s) * 3);
+
+  for (; *s; s++) {
+    char c = *s;
+
+    if (c == ' ')
+      lw_writec_unsafe(ctx, '+');
+    else if (isalnum(c))
+      lw_writec_unsafe(ctx, c);
+    else {
+      sprintf(ctx->page_front, "%%%02X", c);
+      ctx->page_front += 3;
+    }
+  }
+}
+
+void lw_Basis_urlifyBool_w(lw_context ctx, lw_Basis_bool b) {
+  if (b == lw_Basis_False)
+    lw_writec(ctx, '0');
+  else
+    lw_writec(ctx, '1');
+}
+
+
+static char *lw_unurlify_advance(char *s) {
+  char *new_s = strchr(s, '/');
+
+  if (new_s)
+    *new_s++ = 0;
+  else
+    new_s = strchr(s, 0);
+
+  return new_s;
+}
+
+lw_Basis_int lw_Basis_unurlifyInt(lw_context ctx, char **s) {
+  char *new_s = lw_unurlify_advance(*s);
+  int r;
+
+  r = atoi(*s);
+  *s = new_s;
+  return r;
+}
+
+lw_Basis_float lw_Basis_unurlifyFloat(lw_context ctx, char **s) {
+  char *new_s = lw_unurlify_advance(*s);
+  int r;
+
+  r = atof(*s);
+  *s = new_s;
+  return r;
+}
+
+static lw_Basis_string lw_unurlifyString_to(lw_context ctx, char *r, char *s) {
+  char *s1, *s2;
+  int n;
+
+  for (s1 = r, s2 = s; *s2; ++s1, ++s2) {
+    char c = *s2;
+
+    switch (c) {
+    case '+':
+      *s1 = ' ';
+      break;
+    case '%':
+      if (s2[1] == 0)
+        lw_error(ctx, FATAL, "Missing first character of escaped URL byte");
+      if (s2[2] == 0)
+        lw_error(ctx, FATAL, "Missing second character of escaped URL byte");
+      if (sscanf(s2+1, "%02X", &n) != 1)
+        lw_error(ctx, FATAL, "Invalid escaped URL byte starting at: %s", s2);
+      *s1 = n;
+      s2 += 2;
+      break;
+    default:
+      *s1 = c;
+    }
+  }
+  *s1++ = 0;
+  return s1;
+}
+
+lw_Basis_bool lw_Basis_unurlifyBool(lw_context ctx, char **s) {
+  char *new_s = lw_unurlify_advance(*s);
+  lw_Basis_bool r;
+  
+  if (*s[0] == 0 || !strcmp(*s, "0") || !strcmp(*s, "off"))
+    r = lw_Basis_False;
+  else
+    r = lw_Basis_True;
+
+  *s = new_s;
+  return r;
+}
+
+lw_Basis_string lw_Basis_unurlifyString(lw_context ctx, char **s) {
+  char *new_s = lw_unurlify_advance(*s);
+  char *r, *s1, *s2;
+  int len, n;
+
+  len = strlen(*s);
+  lw_check_heap(ctx, len + 1);
+
+  r = ctx->heap_front;
+  ctx->heap_front = lw_unurlifyString_to(ctx, ctx->heap_front, *s);
+  *s = new_s;
+  return r;
+}
+
+
+char *lw_Basis_htmlifyString(lw_context ctx, lw_Basis_string s) {
+  char *r, *s2;
+
+  lw_check_heap(ctx, strlen(s) * 5 + 1);
+
+  for (r = s2 = ctx->heap_front; *s; s++) {
+    char c = *s;
+
+    switch (c) {
+    case '<':
+      strcpy(s2, "&lt;");
+      s2 += 4;
+      break;
+    case '&':
+      strcpy(s2, "&amp;");
+      s2 += 5;
+      break;
+    default:
+      if (isprint(c))
+        *s2++ = c;
+      else {
+        int len2;
+        sprintf(s2, "&#%d;%n", c, &len2);
+        s2 += len2;
+      }
+    }
+  }
+
+  *s2++ = 0;
+  ctx->heap_front = s2;
+  return r;
+}
+
+void lw_Basis_htmlifyString_w(lw_context ctx, lw_Basis_string s) {
+  lw_check(ctx, strlen(s) * 5);
+
+  for (; *s; s++) {
+    char c = *s;
+
+    switch (c) {
+    case '<':
+      lw_write_unsafe(ctx, "&lt;");
+      break;
+    case '&':
+      lw_write_unsafe(ctx, "&amp;");
+      break;
+    default:
+      if (isprint(c))
+        lw_writec_unsafe(ctx, c);
+      else {
+        lw_write_unsafe(ctx, "&#");
+        lw_Basis_attrifyInt_w_unsafe(ctx, c);
+        lw_writec_unsafe(ctx, ';');
+      }
+    }
+  }
+}
+
+lw_Basis_string lw_Basis_strcat(lw_context ctx, lw_Basis_string s1, lw_Basis_string s2) {
+  int len = strlen(s1) + strlen(s2) + 1;
+  char *s;
+
+  lw_check_heap(ctx, len);
+
+  s = ctx->heap_front;
+
+  strcpy(s, s1);
+  strcat(s, s2);
+  ctx->heap_front += len;
+
+  return s;
+}