Merge pull request #892 from bettio/atom-table-revamp

New atom table implementation

Implement new atom table that overcomes previous implementation shortcomings.

Some further improvements are not part of this PR and they will be addressed
with further PRs, such as:

- Using gperf for default atoms
- Removing `atom_table_get_atom_string`
- Coalescing together atom strings that are allocated on the heap (instead of
using `strdup`)

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Shorten UART config options, such as `tx_pin` -> `tx`
 - Introduced support to non-integer peripheral names, `"i2c0"`, `"uart1"` (instead of just `0` and
 - `1`, which now they are deprecated)
+- New atom table, which uses less memory, has improved performances and better code.
 
 ## [0.6.0-alpha.2] - 2023-12-10
 

src/libAtomVM/CMakeLists.txt

@@ -24,6 +24,7 @@ project (libAtomVM)
 set(HEADER_FILES
     atom.h
     atomshashtable.h
+    atom_table.h
     avmpack.h
     bif.h
     bitstring.h
@@ -69,6 +70,7 @@ set(HEADER_FILES
 set(SOURCE_FILES
     atom.c
     atomshashtable.c
+    atom_table.c
     avmpack.c
     bif.c
     bitstring.c

src/libAtomVM/atom.c

@@ -30,7 +30,7 @@ void atom_string_to_c(AtomString atom_string, char *buf, size_t bufsize)
 {
     size_t atom_len = *((const uint8_t *) atom_string);
 
-    if (bufsize < atom_len) {
+    if (bufsize <= atom_len) {
         atom_len = bufsize - 1;
     }
     memcpy(buf, ((const uint8_t *) atom_string) + 1, atom_len);