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circuitpython/py/qstr.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include "py/gc.h"
#include "py/mpstate.h"
#include "py/qstr.h"
#include "py/gc.h"
#include "py/runtime.h"
#include "supervisor/linker.h"
#include "supervisor/shared/translate/translate.h"
// NOTE: we are using linear arrays to store and search for qstr's (unique strings, interned strings)
// ultimately we will replace this with a static hash table of some kind
#if MICROPY_DEBUG_VERBOSE // print debugging info
#define DEBUG_printf DEBUG_printf
#else // don't print debugging info
#define DEBUG_printf(...) (void)0
#endif
// A qstr is an index into the qstr pool.
// The data for a qstr is \0 terminated (so they can be printed using printf)
#define Q_HASH_MASK ((1 << (8 * MICROPY_QSTR_BYTES_IN_HASH)) - 1)
#if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
#define QSTR_ENTER() mp_thread_mutex_lock(&MP_STATE_VM(qstr_mutex), 1)
#define QSTR_EXIT() mp_thread_mutex_unlock(&MP_STATE_VM(qstr_mutex))
#else
#define QSTR_ENTER()
#define QSTR_EXIT()
#endif
// Initial number of entries for qstr pool, set so that the first dynamically
// allocated pool is twice this size. The value here must be <= MP_QSTRnumber_of.
#define MICROPY_ALLOC_QSTR_ENTRIES_INIT (10)
// this must match the equivalent function in makeqstrdata.py
mp_uint_t qstr_compute_hash(const byte *data, size_t len) {
// djb2 algorithm; see http://www.cse.yorku.ca/~oz/hash.html
mp_uint_t hash = 5381;
for (const byte *top = data + len; data < top; data++) {
hash = ((hash << 5) + hash) ^ (*data); // hash * 33 ^ data
}
hash &= Q_HASH_MASK;
// Make sure that valid hash is never zero, zero means "hash not computed"
if (hash == 0) {
hash++;
}
return hash;
}
#ifndef CIRCUITPY_PRECOMPUTE_QSTR_ATTR
#define CIRCUITPY_PRECOMPUTE_QSTR_ATTR (1)
#endif
#if CIRCUITPY_PRECOMPUTE_QSTR_ATTR == 1
const qstr_attr_t mp_qstr_const_attr[MP_QSTRnumber_of] = {
#ifndef NO_QSTR
#define QDEF(id, hash, len, str) { hash, len },
#define TRANSLATION(id, length, compressed ...)
#include "genhdr/qstrdefs.generated.h"
#undef TRANSLATION
#undef QDEF
#endif
};
#else
qstr_attr_t mp_qstr_const_attr[MP_QSTRnumber_of];
#endif
const qstr_pool_t mp_qstr_const_pool = {
NULL, // no previous pool
0, // no previous pool
MICROPY_ALLOC_QSTR_ENTRIES_INIT,
MP_QSTRnumber_of, // corresponds to number of strings in array just below
(qstr_attr_t *)mp_qstr_const_attr,
{
#ifndef NO_QSTR
#define QDEF(id, hash, len, str) str,
#define TRANSLATION(id, length, compressed ...)
#include "genhdr/qstrdefs.generated.h"
#undef TRANSLATION
#undef QDEF
#endif
},
};
#ifdef MICROPY_QSTR_EXTRA_POOL
extern const qstr_pool_t MICROPY_QSTR_EXTRA_POOL;
#define CONST_POOL MICROPY_QSTR_EXTRA_POOL
#else
#define CONST_POOL mp_qstr_const_pool
#endif
void qstr_init(void) {
MP_STATE_VM(last_pool) = (qstr_pool_t *)&CONST_POOL; // we won't modify the const_pool since it has no allocated room left
MP_STATE_VM(qstr_last_chunk) = NULL;
#if CIRCUITPY_PRECOMPUTE_QSTR_ATTR == 0
if (mp_qstr_const_attr[MP_QSTR_circuitpython].len == 0) {
for (size_t i = 0; i < mp_qstr_const_pool.len; i++) {
size_t len = strlen(mp_qstr_const_pool.qstrs[i]);
mp_qstr_const_attr[i].hash = qstr_compute_hash((const byte *)mp_qstr_const_pool.qstrs[i], len);
mp_qstr_const_attr[i].len = len;
}
}
#endif
#if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
mp_thread_mutex_init(&MP_STATE_VM(qstr_mutex));
#endif
}
STATIC const char *find_qstr(qstr q, qstr_attr_t *attr) {
// search pool for this qstr
// total_prev_len==0 in the final pool, so the loop will always terminate
const qstr_pool_t *pool = MP_STATE_VM(last_pool);
while (q < pool->total_prev_len) {
pool = pool->prev;
}
q -= pool->total_prev_len;
assert(q < pool->len);
*attr = pool->attrs[q];
return pool->qstrs[q];
}
// qstr_mutex must be taken while in this function
STATIC qstr qstr_add(mp_uint_t hash, mp_uint_t len, const char *q_ptr) {
DEBUG_printf("QSTR: add hash=%d len=%d data=%.*s\n", hash, len, len, q_ptr);
// make sure we have room in the pool for a new qstr
if (MP_STATE_VM(last_pool)->len >= MP_STATE_VM(last_pool)->alloc) {
uint32_t new_pool_length = MP_STATE_VM(last_pool)->alloc * 2;
if (new_pool_length > MICROPY_QSTR_POOL_MAX_ENTRIES) {
new_pool_length = MICROPY_QSTR_POOL_MAX_ENTRIES;
}
#ifdef MICROPY_QSTR_EXTRA_POOL
// Put a lower bound on the allocation size in case the extra qstr pool has few entries
if (new_pool_length < MICROPY_ALLOC_QSTR_ENTRIES_INIT) {
new_pool_length = MICROPY_ALLOC_QSTR_ENTRIES_INIT;
}
#endif
mp_uint_t pool_size = sizeof(qstr_pool_t)
+ (sizeof(const char *) + sizeof(qstr_attr_t)) * new_pool_length;
qstr_pool_t *pool = (qstr_pool_t *)m_malloc_maybe(pool_size, true);
if (pool == NULL) {
// Keep qstr_last_chunk consistent with qstr_pool_t: qstr_last_chunk is not scanned
// at garbage collection since it's reachable from a qstr_pool_t. And the caller of
// this function expects q_ptr to be stored in a qstr_pool_t so it can be reached
// by the collector. If qstr_pool_t allocation failed, qstr_last_chunk needs to be
// NULL'd. Otherwise it may become a dangling pointer at the next garbage collection.
MP_STATE_VM(qstr_last_chunk) = NULL;
QSTR_EXIT();
m_malloc_fail(new_pool_length);
}
pool->attrs = (qstr_attr_t *)(pool->qstrs + new_pool_length);
pool->prev = MP_STATE_VM(last_pool);
pool->total_prev_len = MP_STATE_VM(last_pool)->total_prev_len + MP_STATE_VM(last_pool)->len;
pool->alloc = new_pool_length;
pool->len = 0;
MP_STATE_VM(last_pool) = pool;
DEBUG_printf("QSTR: allocate new pool of size %d\n", MP_STATE_VM(last_pool)->alloc);
}
// add the new qstr
mp_uint_t at = MP_STATE_VM(last_pool)->len;
MP_STATE_VM(last_pool)->attrs[at].hash = hash;
MP_STATE_VM(last_pool)->attrs[at].len = len;
MP_STATE_VM(last_pool)->qstrs[at] = q_ptr;
MP_STATE_VM(last_pool)->len++;
// return id for the newly-added qstr
return MP_STATE_VM(last_pool)->total_prev_len + at;
}
qstr qstr_find_strn(const char *str, size_t str_len) {
// work out hash of str
mp_uint_t str_hash = qstr_compute_hash((const byte *)str, str_len);
// search pools for the data
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL; pool = pool->prev) {
qstr_attr_t *attrs = pool->attrs;
for (mp_uint_t at = 0, top = pool->len; at < top; at++) {
if (attrs[at].hash == str_hash && attrs[at].len == str_len && memcmp(pool->qstrs[at], str, str_len) == 0) {
return pool->total_prev_len + at;
}
}
}
// not found; return null qstr
return 0;
}
qstr qstr_from_str(const char *str) {
return qstr_from_strn(str, strlen(str));
}
qstr qstr_from_strn(const char *str, size_t len) {
QSTR_ENTER();
qstr q = qstr_find_strn(str, len);
if (q == 0) {
// qstr does not exist in interned pool so need to add it
// check that len is not too big
if (len >= (1 << (8 * MICROPY_QSTR_BYTES_IN_LEN))) {
QSTR_EXIT();
mp_raise_msg(&mp_type_RuntimeError, MP_ERROR_TEXT("Name too long"));
}
// compute number of bytes needed to intern this string
size_t n_bytes = len + 1;
if (MP_STATE_VM(qstr_last_chunk) != NULL && MP_STATE_VM(qstr_last_used) + n_bytes > MP_STATE_VM(qstr_last_alloc)) {
// not enough room at end of previously interned string so try to grow
char *new_p = m_renew_maybe(char, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_alloc) + n_bytes, false);
if (new_p == NULL) {
// could not grow existing memory; shrink it to fit previous
(void)m_renew_maybe(char, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_used), false);
MP_STATE_VM(qstr_last_chunk) = NULL;
} else {
// could grow existing memory
MP_STATE_VM(qstr_last_alloc) += n_bytes;
}
}
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
// no existing memory for the interned string so allocate a new chunk
size_t al = n_bytes;
if (al < MICROPY_ALLOC_QSTR_CHUNK_INIT) {
al = MICROPY_ALLOC_QSTR_CHUNK_INIT;
}
MP_STATE_VM(qstr_last_chunk) = m_new_ll_maybe(char, al);
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
// failed to allocate a large chunk so try with exact size
MP_STATE_VM(qstr_last_chunk) = m_new_ll_maybe(char, n_bytes);
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
QSTR_EXIT();
m_malloc_fail(n_bytes);
}
al = n_bytes;
}
MP_STATE_VM(qstr_last_alloc) = al;
MP_STATE_VM(qstr_last_used) = 0;
}
// allocate memory from the chunk for this new interned string's data
char *q_ptr = MP_STATE_VM(qstr_last_chunk) + MP_STATE_VM(qstr_last_used);
MP_STATE_VM(qstr_last_used) += n_bytes;
// store the interned strings' data
mp_uint_t hash = qstr_compute_hash((const byte *)str, len);
memcpy(q_ptr, str, len);
q_ptr[len] = '\0';
q = qstr_add(hash, len, q_ptr);
}
QSTR_EXIT();
return q;
}
mp_uint_t PLACE_IN_ITCM(qstr_hash)(qstr q) {
qstr_attr_t attr;
find_qstr(q, &attr);
return attr.hash;
}
size_t qstr_len(qstr q) {
qstr_attr_t attr;
find_qstr(q, &attr);
return attr.len;
}
const char *qstr_str(qstr q) {
qstr_attr_t attr;
return find_qstr(q, &attr);
}
const byte *qstr_data(qstr q, size_t *len) {
qstr_attr_t attr;
const char *qd = find_qstr(q, &attr);
*len = attr.len;
return (byte *)qd;
}
void qstr_pool_info(size_t *n_pool, size_t *n_qstr, size_t *n_str_data_bytes, size_t *n_total_bytes) {
QSTR_ENTER();
*n_pool = 0;
*n_qstr = 0;
*n_str_data_bytes = 0;
*n_total_bytes = 0;
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL && pool != &CONST_POOL; pool = pool->prev) {
*n_pool += 1;
*n_qstr += pool->len;
for (const qstr_attr_t *q = pool->attrs, *q_top = pool->attrs + pool->len; q < q_top; q++) {
*n_str_data_bytes += sizeof(*q) + q->len + 1;
}
#if MICROPY_ENABLE_GC
// this counts actual bytes used in heap
*n_total_bytes += gc_nbytes(pool) - sizeof(qstr_attr_t) * pool->alloc;
#else
*n_total_bytes += sizeof(qstr_pool_t) + sizeof(const char *) * pool->alloc;
#endif
}
*n_total_bytes += *n_str_data_bytes;
QSTR_EXIT();
}
#if MICROPY_PY_MICROPYTHON_MEM_INFO
void qstr_dump_data(void) {
QSTR_ENTER();
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL && pool != &CONST_POOL; pool = pool->prev) {
for (const char *const *q = pool->qstrs, *const *q_top = pool->qstrs + pool->len; q < q_top; q++) {
mp_printf(&mp_plat_print, "Q(%s)\n", *q);
}
}
QSTR_EXIT();
}
#endif
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