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general cleanup

master
John Jones 2016-11-07 17:05:49 -05:00
parent 4e1b3171fb
commit 904cdf6871
6 changed files with 110 additions and 26 deletions
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11
include/mh/hashes.h
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@ -31,7 +31,16 @@ static const int mh_all_hashes[] = {
#define MH_H_COUNT (int)(sizeof(mh_all_hashes) / sizeof(mh_all_hashes[0]))
/**
* Given the id, return the hash name
* @param hash the id (such as MH_H_SHA1)
* @returns the name as text, such as "sha1"
*/
const char *mh_hash_name(int hash);
// returns length in bytes or if returns is < 0 it is an error
/**
* Given the id, return the default length
* @param hash the id
* @returns the default length of that hash
*/
int mh_hash_default_length(int hash);

42
include/mh/multihash.h
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@ -3,25 +3,47 @@
#include <stddef.h>
// returns hash code or error (which is < 0)
/**
* returns hash code or error (which is < 0)
* @param mh the multihash
* @param len the length of the multihash
* @returns errors ( < 0 ) or the multihash
*/
int mh_multihash_hash(const unsigned char *multihash, size_t len);
// returns length of multihash or error (which is < 0)
/***
* returns the length of the multihash's data section
* @param mh the multihash
* @param len the length of the multihash
* @returns the length of the data section, or an error if < 0
*/
int mh_multihash_length(const unsigned char *multihash, size_t len);
// gives access to raw digest inside multihash buffer
// returns 0 or negative error
/**
* gives access to raw digest inside multihash buffer
* @param multihash the multihash
* @param len the length
* @param digest the results
* @returns error if less than zero, otherwise 0
*/
int mh_multihash_digest(unsigned char *multihash, size_t len,
unsigned char **digest, size_t *digest_len);
// returns length in bytes of buffer needed to store multihash
// with given hashcode and with given digest length
// returns length or negative error code
/**
* determine the size of the multihash given the data size
* @param code currently not used
* @param hash_len the data size
* @returns hash_len + 2 (until the code parameter (varint) is added
*/
int mh_new_length(int code, size_t digest_len);
// writes multihash into a buffer, the buffer needs to be at least
// mh_new_length() bytes long.
// returns negative error code or 0
/***
* create a multihash based on some data
* @param buffer where to put the multihash
* @param code the code
* @param digest the data within the multihash
* @returns error (if < 0) or 0
*/
int mh_new(unsigned char *buffer, int code, const unsigned char *digest,
size_t digest_len);

5
src/errors.c
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@ -1,5 +1,10 @@
#include "mh/errors.h"
/**
* Convert an error code into a string
* @param code the error code
* @returns the error as text
*/
const char *mh_error_string(int code) {
switch (code) {
case MH_E_NO_ERROR:

21
src/hashes.c
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@ -1,3 +1,7 @@
/***
* Some helpers in identifying hashes
*/
#include <stdlib.h>
#include "mh/hashes.h"
@ -26,7 +30,11 @@ static const struct hash_info {
mh_assert_static(sizeof(hash_infos) / sizeof(hash_infos[0]) == MH_H_COUNT);
// Searches for given hash in hash info table
/**
* Given the id, return a struct that shows the id, name, and default length
* @param hash the id, such as MH_H_SHA1
* @returns a hash_info struct that has an int, const char* and int
*/
static const struct hash_info *find_hash(int hash) {
// naive search, could be replaced with binary
unsigned int i = 0;
@ -38,12 +46,21 @@ static const struct hash_info *find_hash(int hash) {
return NULL;
}
/**
* Given the id, return the hash name
* @param hash the id (such as MH_H_SHA1)
* @returns the name as text, such as "sha1"
*/
const char *mh_hash_name(int hash) {
const struct hash_info *info = find_hash(hash);
return (info != NULL) ? info->name : NULL;
}
/**
* Given the id, return the default length
* @param hash the id
* @returns the default length of that hash
*/
int mh_hash_default_length(int hash) {
const struct hash_info *info = find_hash(hash);
return (info != NULL) ? info->length : MH_E_UNKNOWN_CODE;

6
src/main.c
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@ -1,6 +0,0 @@
#include <stdio.h>
int main(void) {
printf("Hello World\n");
return 0;
}

51
src/multihash.c
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@ -9,6 +9,11 @@
#define VARINT_MASK (1 << 7)
/**
* checks the length of a multihash for validity
* @param len the length of the multihash
* @returns errors or MH_E_NO_ERROR(0)
*/
static int check_len(size_t len) {
if (len < 1)
return MH_E_TOO_SHORT;
@ -18,6 +23,12 @@ static int check_len(size_t len) {
return MH_E_NO_ERROR;
}
/**
* do some general checks on the multihash for validity
* @param mh the multihash
* @param len the length of the multihash
* @returns errors or MH_E_NO_ERROR(0)
*/
static int check_multihash(const unsigned char mh[], size_t len) {
int err;
@ -33,14 +44,17 @@ static int check_multihash(const unsigned char mh[], size_t len) {
}
err = check_len(mh[1]);
if (err)
return err;
return 0;
return err;
}
// returns hash code or error (which is < 0)
/**
* returns hash code or error (which is < 0)
* @param mh the multihash
* @param len the length of the multihash
* @returns errors ( < 0 ) or the multihash
*/
int mh_multihash_hash(const unsigned char *mh, size_t len) {
int err = check_multihash(mh, len);
if (err)
@ -50,7 +64,12 @@ int mh_multihash_hash(const unsigned char *mh, size_t len) {
}
// returns length of multihash or error (which is < 0)
/***
* returns the length of the multihash's data section
* @param mh the multihash
* @param len the length of the multihash
* @returns the length of the data section, or an error if < 0
*/
int mh_multihash_length(const unsigned char *mh, size_t len) {
int err = check_multihash(mh, len);
if (err)
@ -59,8 +78,13 @@ int mh_multihash_length(const unsigned char *mh, size_t len) {
return (int) mh[1];
}
// gives access to raw digest inside multihash buffer
// returns 0 or negative error
/**
* gives access to raw digest inside multihash buffer
* @param multihash the multihash
* @param len the length
* @param digest the results
* @returns error if less than zero, otherwise 0
*/
int mh_multihash_digest(unsigned char *multihash, size_t len, unsigned char **digest,
size_t *digest_len) {
int err = check_multihash(multihash, len);
@ -73,6 +97,12 @@ int mh_multihash_digest(unsigned char *multihash, size_t len, unsigned char **di
return 0;
}
/**
* determine the size of the multihash given the data size
* @param code currently not used
* @param hash_len the data size
* @returns hash_len + 2 (until the code parameter (varint) is added
*/
int mh_new_length(int code, size_t hash_len) {
// right now there is no varint support
// so length required is 2 + hash_len
@ -80,6 +110,13 @@ int mh_new_length(int code, size_t hash_len) {
return 2 + hash_len;
}
/***
* create a multihash based on some data
* @param buffer where to put the multihash
* @param code the code
* @param digest the data within the multihash
* @returns error (if < 0) or 0
*/
int mh_new(unsigned char *buffer, int code, const unsigned char *digest,
size_t digest_len) {
if (code & VARINT_MASK)