1 files changed, 178 insertions, 0 deletions
diff --git a/src/constmap.c b/src/constmap.c
new file mode 100644
index 0000000..4b2eb87
--- /dev/null
+++ b/src/constmap.c
@@ -0,0 +1,178 @@
+#include "constmap.h"
+#include "alloc.h"
+#include "case.h"
+
+/**
+  * @file constmap.c
+  * @author djb
+  * @ref qmail
+  * @brief constant hash table
+  * @brief Attention! constmap is both function and struct
+  */
+
+
+static constmap_hash hash(char *s,int len)
+{
+  unsigned char ch;
+  constmap_hash h;
+  h = 5381;
+  while (len > 0) {
+    ch = *s++ - 'A';
+    if (ch <= 'Z' - 'A') ch += 'a' - 'A';
+    h = ((h << 5) + h) ^ ch;
+    --len;
+  }
+  return h;
+}
+
+char *constmap(struct constmap *cm,char *s,int len)
+{
+  constmap_hash h;
+  int pos;
+  h = hash(s,len);
+  pos = cm->first[h & cm->mask];
+  while (pos != -1) {
+    if (h == cm->hash[pos])
+      if (len == cm->inputlen[pos])
+        if (!case_diffb(cm->input[pos],len,s))
+          return cm->input[pos] + cm->inputlen[pos] + 1;
+    pos = cm->next[pos];
+  }
+  return 0;
+}
+
+int constmap_init(struct constmap *cm,char *s,int len,int flagcolon)
+{
+  int i;
+  int j;
+  int k;
+  int pos;
+  constmap_hash h;
+ 
+  cm->num = 0;
+  for (j = 0; j < len; ++j) if (!s[j]) ++cm->num;
+ 
+  h = 64;
+  while (h && (h < cm->num)) h += h;
+  cm->mask = h - 1;
+ 
+  cm->first = (int *) alloc(sizeof(int) * h);
+  if (cm->first) {
+    cm->input = (char **) alloc(sizeof(char *) * cm->num);
+    if (cm->input) {
+      cm->inputlen = (int *) alloc(sizeof(int) * cm->num);
+      if (cm->inputlen) {
+        cm->hash = (constmap_hash *) alloc(sizeof(constmap_hash) * cm->num);
+        if (cm->hash) {
+          cm->next = (int *) alloc(sizeof(int) * cm->num);
+          if (cm->next) {
+            for (h = 0; h <= cm->mask; ++h)
+               cm->first[h] = -1;
+            pos = 0;
+            i = 0;
+            for (j = 0; j < len; ++j)
+              if (!s[j]) {
+                k = j - i;
+                if (flagcolon) {
+                  for (k = i; k < j; ++k)
+                    if (s[k] == ':') break;
+                  if (k >= j) { i = j + 1; continue; }
+                  k -= i;
+                }
+                cm->input[pos] = s + i;
+                cm->inputlen[pos] = k;
+                h = hash(s + i,k);
+                cm->hash[pos] = h;
+                h &= cm->mask;
+                cm->next[pos] = cm->first[h];
+                cm->first[h] = pos;
+                ++pos;
+                i = j + 1;
+              }
+            return 1;
+          }
+          alloc_free(cm->hash);
+        }
+        alloc_free(cm->inputlen);
+      }
+      alloc_free(cm->input);
+    }
+    alloc_free(cm->first);
+  }
+  return 0;
+}
+
+int constmap_init_char(struct constmap *cm,char *s,int len,int flagcolon,char flagchar)
+{
+  int i;
+  int j;
+  int k;
+  int pos;
+  constmap_hash h;
+
+  if (!flagchar || flagchar == 0 || flagchar == '\0') {
+    flagchar = ':';
+  }
+
+  cm->num = 0;
+  for (j = 0; j < len; ++j) if (!s[j]) ++cm->num;
+
+  h = 64;
+  while (h && (h < cm->num)) h += h;
+  cm->mask = h - 1;
+
+  cm->first = (int *) alloc(sizeof(int) * h);
+  if (cm->first) {
+    cm->input = (char **) alloc(sizeof(char *) * cm->num);
+    if (cm->input) {
+      cm->inputlen = (int *) alloc(sizeof(int) * cm->num);
+      if (cm->inputlen) {
+        cm->hash = (constmap_hash *) alloc(sizeof(constmap_hash) * cm->num);
+        if (cm->hash) {
+          cm->next = (int *) alloc(sizeof(int) * cm->num);
+          if (cm->next) {
+            for (h = 0; h <= cm->mask; ++h)
+              cm->first[h] = -1;
+            pos = 0;
+            i = 0;
+            for (j = 0; j < len; ++j) {
+              if (!s[j]) {
+                k = j - i;
+                if (flagcolon) {
+                  for (k = i; k < j; ++k)
+                    if (s[k] == flagchar) break;
+                  if (k >= j) { i = j + 1; continue; }
+                  k -= i;
+                }
+                cm->input[pos] = s + i;
+                cm->inputlen[pos] = k;
+                h = hash(s + i,k);
+                cm->hash[pos] = h;
+                h &= cm->mask;
+                cm->next[pos] = cm->first[h];
+                cm->first[h] = pos;
+                ++pos;
+                i = j + 1;
+              }
+            }
+            return 1;
+          }
+          alloc_free(cm->hash);
+        }
+        alloc_free(cm->inputlen);
+      }
+      alloc_free(cm->input);
+    }
+    alloc_free(cm->first);
+  }
+  return 0;
+}
+
+void constmap_free(struct constmap *cm)
+{
+  alloc_free(cm->next);
+  alloc_free(cm->hash);
+  alloc_free(cm->inputlen);
+  alloc_free(cm->input);
+  alloc_free(cm->first);
+}