depmod: point to documentation in libkmod

Instead of repeating all documentation, point to the documentation
available in libkmod-index.c

This also removes INDEX_PRIORITY_MIN that was not being used.

diff --git a/tools/depmod.c b/tools/depmod.c
index fec458c..9669a61 100644 (file)
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -142,84 +142,13 @@ static inline void _show(const char *fmt, ...)
  *   along with these programs.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* Integers are stored as 32 bit unsigned in "network" order, i.e. MSB first.
-   All files start with a magic number.
+/* see documentation in libkmod/libkmod-index.c */
 
-   Magic spells "BOOTFAST". Second one used on newer versioned binary files.
- */
-/* #define INDEX_MAGIC_OLD 0xB007FA57 */
 #define INDEX_MAGIC 0xB007F457
-
-/* We use a version string to keep track of changes to the binary format
- * This is stored in the form: INDEX_MAJOR (hi) INDEX_MINOR (lo) just in
- * case we ever decide to have minor changes that are not incompatible.
- */
-
 #define INDEX_VERSION_MAJOR 0x0002
 #define INDEX_VERSION_MINOR 0x0001
 #define INDEX_VERSION ((INDEX_VERSION_MAJOR<<16)|INDEX_VERSION_MINOR)
-
-/* The index file maps keys to values. Both keys and values are ASCII strings.
-   Each key can have multiple values. Values are sorted by an integer priority.
-
-   The reader also implements a wildcard search (including range expressions)
-   where the keys in the index are treated as patterns.
-   This feature is required for module aliases.
-*/
-
-/* Implementation is based on a radix tree, or "trie".
-   Each arc from parent to child is labelled with a character.
-   Each path from the root represents a string.
-
-   == Example strings ==
-
-   ask
-   ate
-   on
-   once
-   one
-
-   == Key ==
-    + Normal node
-    * Marked node, representing a key and it's values.
-
-   +
-   |-a-+-s-+-k-*
-   |   |
-   |   `-t-+-e-*
-   |
-   `-o-+-n-*-c-+-e-*
-           |
-           `-e-*
-
-   Naive implementations tend to be very space inefficient; child pointers
-   are stored in arrays indexed by character, but most child pointers are null.
-
-   Our implementation uses a scheme described by Wikipedia as a Patrica trie,
-
-       "easiest to understand as a space-optimized trie where
-        each node with only one child is merged with its child"
-
-   +
-   |-a-+-sk-*
-   |   |
-   |   `-te-*
-   |
-   `-on-*-ce-*
-        |
-        `-e-*
-
-   We still use arrays of child pointers indexed by a single character;
-   the remaining characters of the label are stored as a "prefix" in the child.
-
-   The paper describing the original Patrica trie works on individiual bits -
-   each node has a maximum of two children, which increases space efficiency.
-   However for this application it is simpler to use the ASCII character set.
-   Since the index file is read-only, it can be compressed by omitting null
-   child pointers at the start and end of arrays.
-*/
-
-#define INDEX_PRIORITY_MIN UINT32_MAX
+#define INDEX_CHILDMAX 128
 
 struct index_value {
        struct index_value *next;
@@ -228,8 +157,6 @@ struct index_value {
 };
 
 /* In-memory index (depmod only) */
-
-#define INDEX_CHILDMAX 128
 struct index_node {
        char *prefix;           /* path compression */
        struct index_value *values;
@@ -238,32 +165,6 @@ struct index_node {
        struct index_node *children[INDEX_CHILDMAX]; /* indexed by character */
 };
 
-/* Disk format:
-
-   uint32_t magic = INDEX_MAGIC;
-   uint32_t version = INDEX_VERSION;
-   uint32_t root_offset;
-
-   (node_offset & INDEX_NODE_MASK) specifies the file offset of nodes:
-
-        char[] prefix; // nul terminated
-
-        char first;
-        char last;
-        uint32_t children[last - first + 1];
-
-        uint32_t value_count;
-        struct {
-            uint32_t priority;
-            char[] value; // nul terminated
-        } values[value_count];
-
-   (node_offset & INDEX_NODE_FLAGS) indicates which fields are present.
-   Empty prefixes are omitted, leaf nodes omit the three child-related fields.
-
-   This could be optimised further by adding a sparse child format
-   (indicated using a new flag).
- */
 
 /* Format of node offsets within index file */
 enum node_offset {