From 5465eb3accf8661675ff4c9111328077276fee98 Mon Sep 17 00:00:00 2001
From: Cedric BAIL <cedric.bail@samsung.com>
Date: Fri, 5 Apr 2013 12:14:50 +0900
Subject: [PATCH] eet: remove use of prev to reduce memory usage (30KB on
 32bits system).

---
 src/lib/eet/Eet_private.h    |  1 -
 src/lib/eet/eet_dictionary.c | 23 +++++++++++++----------
 src/lib/eet/eet_lib.c        | 12 +++++++++---
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/src/lib/eet/Eet_private.h b/src/lib/eet/Eet_private.h
index 87d66c4..af4f75e 100644
--- a/src/lib/eet/Eet_private.h
+++ b/src/lib/eet/Eet_private.h
@@ -32,7 +32,6 @@ struct _Eet_String
    int           len;
 
    int           next;
-   int           prev;
 };
 struct _Eet_Dictionary
 {
diff --git a/src/lib/eet/eet_dictionary.c b/src/lib/eet/eet_dictionary.c
index bdf141a..b003616 100644
--- a/src/lib/eet/eet_dictionary.c
+++ b/src/lib/eet/eet_dictionary.c
@@ -52,7 +52,8 @@ static int
 _eet_dictionary_lookup(Eet_Dictionary *ed,
                        const char     *string,
                        int             len,
-                       int             hash)
+                       int             hash,
+                       int            *previous)
 {
    Eina_Bool found = EINA_FALSE;
    int prev = -1;
@@ -78,8 +79,14 @@ _eet_dictionary_lookup(Eet_Dictionary *ed,
      }
 
    if ((current == -1) && found)
-     return prev;
+     {
+        // WTF ?!? How can current == -1 and found == EINA_TRUE
+        // If you happen to trigger this abort, contact enlightenment developer mailing list
+        abort();
+        return prev;
+     }
 
+   if (previous) *previous = prev;
    return current;
 }
 
@@ -91,6 +98,7 @@ eet_dictionary_string_add(Eet_Dictionary *ed,
    const char *str;
    int hash;
    int idx;
+   int pidx;
    int len;
    int cnt;
 
@@ -102,7 +110,7 @@ eet_dictionary_string_add(Eet_Dictionary *ed,
 
    eina_lock_take(&ed->mutex);
 
-   idx = _eet_dictionary_lookup(ed, string, len, hash);
+   idx = _eet_dictionary_lookup(ed, string, len, hash, &pidx);
 
    if (idx != -1)
      {
@@ -153,19 +161,14 @@ eet_dictionary_string_add(Eet_Dictionary *ed,
    if (idx == -1)
      {
         current->next = ed->hash[hash];
-        current->prev = -1;
         ed->hash[hash] = ed->count;
      }
    else
      {
         current->next = idx;
-        current->prev = ed->all[idx].prev;
-
-        if (current->next != -1)
-          ed->all[current->next].prev = ed->count;
 
-        if (current->prev != -1)
-          ed->all[current->prev].next = ed->count;
+        if (pidx != -1)
+          ed->all[pidx].next = ed->count;
         else
           ed->hash[hash] = ed->count;
      }
diff --git a/src/lib/eet/eet_lib.c b/src/lib/eet/eet_lib.c
index fd835af..4716f6a 100644
--- a/src/lib/eet/eet_lib.c
+++ b/src/lib/eet/eet_lib.c
@@ -445,11 +445,16 @@ eet_flush2(Eet_File *ef)
         for (j = 0; j < ef->ed->count; ++j)
           {
              int sbuf[EET_FILE2_DICTIONARY_ENTRY_COUNT];
+	     int prev = 0;
+
+             // We still use the prev as an hint for knowing if it is the head of the hash
+	     if (ef->ed->hash[ef->ed->all_hash[j]] == j)
+	       prev = -1;
 
              sbuf[0] = (int)htonl((unsigned int)ef->ed->all_hash[j]);
              sbuf[1] = (int)htonl((unsigned int)offset);
              sbuf[2] = (int)htonl((unsigned int)ef->ed->all[j].len);
-             sbuf[3] = (int)htonl((unsigned int)ef->ed->all[j].prev);
+             sbuf[3] = (int)htonl((unsigned int)prev);
              sbuf[4] = (int)htonl((unsigned int)ef->ed->all[j].next);
 
              offset += ef->ed->all[j].len;
@@ -959,12 +964,13 @@ eet_internal_read2(Eet_File *ef)
         for (j = 0; j < ef->ed->count; ++j)
           {
              unsigned int offset;
+	     int prev;
              int hash;
 
              GET_INT(hash, dico, idx);
              GET_INT(offset, dico, idx);
              GET_INT(ef->ed->all[j].len, dico, idx);
-             GET_INT(ef->ed->all[j].prev, dico, idx);
+             GET_INT(prev, dico, idx); // Let's ignore prev link for dictionary, use it only as an hint to head
              GET_INT(ef->ed->all[j].next, dico, idx);
 
              /* Hash value could be stored on 8bits data, but this will break alignment of all the others data.
@@ -992,7 +998,7 @@ eet_internal_read2(Eet_File *ef)
                return NULL;
 
              ef->ed->all_hash[j] = hash;
-             if (ef->ed->all[j].prev == -1)
+             if (prev == -1)
                ef->ed->hash[hash] = j;
 
              /* compute the possible position of a signature */
-- 
2.7.4