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ops.c
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ops.c
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#include "platform/memmem.h"
#include "platform/memmem32.h"
#include "moar.h"
#define MVM_DEBUG_STRANDS 0
#define MVM_string_KMP_max_pattern_length 8192
/* Max value possible for MVMuint32 MVMStringBody.num_graphs */
#define MAX_GRAPHEMES 0xFFFFFFFFLL
#if MVM_DEBUG_STRANDS
static void check_strand_sanity(MVMThreadContext *tc, MVMString *s) {
MVMGraphemeIter gi;
MVMuint32 len;
MVM_string_gi_init(tc, &gi, s);
len = 0;
while (MVM_string_gi_has_more(tc, &gi)) {
MVM_string_gi_get_grapheme(tc, &gi);
len++;
}
if (len != MVM_string_graphs(tc, s))
MVM_exception_throw_adhoc(tc,
"Strand sanity check failed (strand length %d != num_graphs %d)",
len, MVM_string_graphs(tc, s));
}
#define STRAND_CHECK(tc, s) check_strand_sanity(tc, s);
#else
#define STRAND_CHECK(tc, s)
#endif
static MVMString * re_nfg(MVMThreadContext *tc, MVMString *in);
#if MVM_DEBUG_NFG
static char * NFG_check_make_debug_string (MVMThreadContext *tc, MVMGrapheme32 g) {
char *result = NULL;
char *picked = NULL;
if (g == '\r')
picked = "\\r";
else if (g == '\n')
picked = "\\n";
else if (g == MVM_nfg_crlf_grapheme(tc))
picked = "\\r\\n";
else if (0 <= g && !MVM_string_is_control_full(tc, g))
result = MVM_string_utf8_encode_C_string(tc, MVM_string_chr(tc, g));
else if (g < 0) {
MVMNFGSynthetic *synth = MVM_nfg_get_synthetic_info(tc, g);
char *format_str = " with num_codes = ";
char *format_str2 = " first, second cp = ";
char *synthtype_str = synth->is_utf8_c8 ? "utf8-8 Synthetic" : "Normal Synthetic";
int this_len = strlen(format_str) + strlen(synthtype_str) + 6 + strlen(format_str2) + 11 + 1 + 11 + 1;
result = MVM_malloc(this_len);
if (2 <= synth->num_codes)
sprintf(result, "%s%s%5i%s%.10"PRIi32",%.10"PRIi32"", synthtype_str, format_str, synth->num_codes, format_str2, synth->codes[0], synth->codes[1]);
else
sprintf(result, "WARNING synth has less than 2 codes");
fprintf(stderr, "synth numcodes %i %"PRIi32"\n",
MVM_nfg_get_synthetic_info(tc, synth->codes[1])->num_codes, MVM_nfg_get_synthetic_info(tc, synth->codes[1])->codes[0]
);
}
else
picked = "[Control]";
if (picked) {
result = MVM_malloc(sizeof(char) * (strlen(picked) + 1));
strcpy(result, picked);
}
if (!result) {
result = MVM_malloc(sizeof(char) * 1);
result[0] = 0;
}
return result;
}
static char * NFG_checker (MVMThreadContext *tc, MVMString *orig, char *varname);
void NFG_check (MVMThreadContext *tc, MVMString *orig, char *varname) {
char *out = NFG_checker(tc, orig, varname);
char *waste[2] = { out, NULL };
if (!out)
return;
MVM_exception_throw_adhoc_free(tc, waste, "%s", out);
}
static char * NFG_checker (MVMThreadContext *tc, MVMString *orig, char *varname) {
MVMString *renorm = NULL;
MVMStringIndex orig_graphs = MVM_string_graphs(tc, orig),
renorm_graphs = -1;
MVMROOT2(tc, orig, renorm, {
renorm = re_nfg(tc, orig);
renorm_graphs = MVM_string_graphs(tc, renorm);
});
if (MVM_DEBUG_NFG_STRICT || orig_graphs != renorm_graphs) {
MVMGraphemeIter orig_gi, renorm_gi;
MVMint64 index = 0;
MVM_string_gi_init(tc, &orig_gi, orig);
MVM_string_gi_init(tc, &renorm_gi, renorm);
while (MVM_string_gi_has_more(tc, &orig_gi) && MVM_string_gi_has_more(tc, &renorm_gi)) {
MVMGrapheme32 orig_g = MVM_string_gi_get_grapheme(tc, &orig_gi),
renorm_g = MVM_string_gi_get_grapheme(tc, &renorm_gi);
if (orig_g != renorm_g) {
char *orig_render = NFG_check_make_debug_string(tc, orig_g),
*renorm_render = NFG_check_make_debug_string(tc, renorm_g);
char *format = "NFG failure. Got different grapheme count of %s. "
"Got %i but after re_nfg got %i\n"
"Differing grapheme at index %"PRIi64"\n"
"orig: %"PRIi32" (%s) after re_nfg: %"PRIi32" (%s)\n";
int out_size = strlen(orig_render) + strlen(renorm_render)
+ strlen(varname) + strlen(format) + (5 * 7) + 1;
char *out = MVM_malloc(sizeof(char) * out_size);
char *waste[] = {orig_render, renorm_render, NULL};
char **w = waste;
snprintf(out, out_size,
format,
varname,
orig_graphs, renorm_graphs,
index,
orig_g, orig_render, renorm_g, renorm_render);
MVM_free(orig_render);
MVM_free(renorm_render);
return out;
}
index++;
}
}
return NULL;
}
void NFG_check_concat (MVMThreadContext *tc, MVMString *result, MVMString *a, MVMString *b, char *varname) {
char *a_out = NFG_checker(tc, a, "string ‘a’");
char *b_out = NFG_checker(tc, b, "string ‘b’");
char *out = NFG_checker(tc, result, varname);
char *strings[] = { a_out, b_out, out };
char *names[] = { "\nconcat string ‘a’: ", "\nconcat string ‘b’: ", "\nconcat result: " };
int i = 0, elems = 4;
int rtrn = 0;
char * empty = "";
if (!a_out && !b_out && !out)
return;
else {
MVMGrapheme32 last_a = MVM_string_get_grapheme_at_nocheck(tc, a, a->body.num_graphs - 1),
first_b = MVM_string_get_grapheme_at_nocheck(tc, b, 0);
char *debug_a = NFG_check_make_debug_string(tc, last_a),
*debug_b = NFG_check_make_debug_string(tc, first_b),
*escaped_a = MVM_string_utf8_encode_C_string(tc, MVM_string_escape(tc, a)),
*escaped_b = MVM_string_utf8_encode_C_string(tc, MVM_string_escape(tc, b)),
*escaped_result = MVM_string_utf8_encode_C_string(tc, MVM_string_escape(tc, result));
char *waste[] = { out, debug_a, debug_b, escaped_a, escaped_b, escaped_result, NULL };
MVM_exception_throw_adhoc_free(tc, waste,
"In concat: a graphs: %"PRIi32" b graphs: %"PRIi32"\n"
"last_a: %"PRIi32" (%s) first_b %"PRIi32" (%s)\n"
"a: “%s”\n"
"b: “%s”\n"
"result: “%s”\n"
"%s%s%s%s%s%s",
MVM_string_graphs(tc, a), MVM_string_graphs(tc, b),
last_a, debug_a, first_b, debug_b,
escaped_a,
escaped_b,
escaped_result,
(a_out?names[0]:""), (a_out?a_out:""),
(b_out?names[1]:""), (b_out?b_out:""),
(out?names[2]:""), (out?out:""));
}
}
#endif
MVM_STATIC_INLINE MVMint64 string_equal_at_ignore_case_INTERNAL_loop(MVMThreadContext *tc, void *Hs_or_gic, MVMString *needle_fc, MVMint64 H_start, MVMint64 H_graphs, MVMint64 n_fc_graphs, int ignoremark, int ignorecase, int is_gic);
static MVMint64 knuth_morris_pratt_string_index (MVMThreadContext *tc, MVMString *needle, MVMString *Haystack, MVMint64 H_offset);
/* Allocates strand storage. */
static MVMStringStrand * allocate_strands(MVMThreadContext *tc, MVMuint16 num_strands) {
return MVM_malloc(num_strands * sizeof(MVMStringStrand));
}
/* Copies strands from one strand string to another. */
static void copy_strands(MVMThreadContext *tc, const MVMString *from, MVMuint16 from_offset,
MVMString *to, MVMuint16 to_offset, MVMuint16 num_strands) {
assert(from->body.storage_type == MVM_STRING_STRAND);
assert(to->body.storage_type == MVM_STRING_STRAND);
memcpy(
to->body.storage.strands + to_offset,
from->body.storage.strands + from_offset,
num_strands * sizeof(MVMStringStrand));
}
/* Move strands inside the same strand string. */
static void move_strands(MVMThreadContext *tc, const MVMString *from, MVMuint16 from_offset,
MVMString *to, MVMuint16 to_offset, MVMuint16 num_strands) {
assert(from->body.storage_type == MVM_STRING_STRAND);
assert(to->body.storage_type == MVM_STRING_STRAND);
memmove(
to->body.storage.strands + to_offset,
from->body.storage.strands + from_offset,
num_strands * sizeof(MVMStringStrand));
}
#define can_fit_into_8bit(g) ((-128 <= (g) && (g) <= 127))
MVM_STATIC_INLINE int can_fit_into_ascii (MVMGrapheme32 g) {
return 0 <= g && g <= 127;
}
/* If a string is currently using 32bit storage, turn it into using
* 8 bit storage. Doesn't do any checks at all. */
static void turn_32bit_into_8bit_unchecked(MVMThreadContext *tc, MVMString *str) {
MVMGrapheme32 *old_buf = str->body.storage.blob_32;
MVMStringIndex i;
MVMGrapheme8 *dest_buf = NULL;
MVMStringIndex num_graphs = MVM_string_graphs_nocheck(tc, str);
str->body.storage_type = MVM_STRING_GRAPHEME_8;
dest_buf = str->body.storage.blob_8 = MVM_malloc(str->body.num_graphs * sizeof(MVMGrapheme8));
MVM_VECTORIZE_LOOP
for (i = 0; i < num_graphs; i++) {
dest_buf[i] = old_buf[i];
}
MVM_free(old_buf);
}
/* Checks if the next num_graphs graphemes in the iterator can fit into 8 bits.
* This was written to take advantage of SIMD vectorization, so we use a multiple
* bitwise operations to check, and biwise OR it with val. Care must be taken
* to not use any variables altered by the loop outside of the loop and to not
* have any branching or funcion calls. `i` is not used outside the loop
* `val` is allowed as biwise OR works with the vectorization well.
* NOTE: GraphemeIter is not modified by this function. */
static int string_can_be_8bit(MVMThreadContext *tc, MVMGraphemeIter *gi_orig, MVMStringIndex num_graphs) {
MVMStringIndex pos = 0;
MVMGraphemeIter gi;
memcpy(&gi, gi_orig, sizeof(MVMGraphemeIter));
while (1) {
MVMStringIndex strand_len = MVM_string_gi_graphs_left_in_strand(tc, &gi);
MVMStringIndex togo = num_graphs - pos < strand_len
? num_graphs - pos
: strand_len;
if (MVM_string_gi_blob_type(tc, &gi) == MVM_STRING_GRAPHEME_32) {
if (!MVM_string_buf32_can_fit_into_8bit(MVM_string_gi_active_blob_32_pos(tc, &gi), togo))
return 0;
}
pos += togo;
if (num_graphs == pos || !MVM_string_gi_has_more_strands_rep(tc, &gi)) {
break;
}
MVM_string_gi_next_strand_rep(tc, &gi);
}
return 1;
}
/* Accepts an allocated string that should have body.num_graphs set but the blob
* unallocated. This function will allocate the space for the blob and iterate
* the supplied grapheme iterator for the length of body.num_graphs. Very fast
* since compilers will convert them to SIMD vector operations. */
static void iterate_gi_into_string(MVMThreadContext *tc, MVMGraphemeIter *gi, MVMString *result, MVMString *orig, MVMStringIndex num) {
int result_pos = 0;
MVMGrapheme8 *result8 = NULL;
MVMGrapheme32 *result32 = NULL;
MVMStringIndex result_graphs = MVM_string_graphs_nocheck(tc, result);
if (!result_graphs)
return;
if (string_can_be_8bit(tc, gi, result_graphs)) {
MVMStringIndex result_pos = 0;
result->body.storage_type = MVM_STRING_GRAPHEME_8;
result8 = result->body.storage.blob_8 =
MVM_malloc(result_graphs * sizeof(MVMGrapheme8));
while (1) {
MVMStringIndex strand_len =
MVM_string_gi_graphs_left_in_strand(tc, gi);
MVMStringIndex to_copy = result_graphs - result_pos < strand_len
? result_graphs - result_pos
: strand_len;
MVMGrapheme8 *result_blob8 = result8 + result_pos;
switch (MVM_string_gi_blob_type(tc, gi)) {
case MVM_STRING_GRAPHEME_32: {
MVMStringIndex i;
MVMGrapheme32 *active_blob =
MVM_string_gi_active_blob_32_pos(tc, gi);
MVM_VECTORIZE_LOOP
for (i = 0; i < to_copy; i++) {
result_blob8[i] = active_blob[i];
}
break;
}
case MVM_STRING_GRAPHEME_8:
case MVM_STRING_GRAPHEME_ASCII: {
memcpy(
result_blob8,
MVM_string_gi_active_blob_8_pos(tc, gi),
to_copy * sizeof(MVMGrapheme8)
);
break;
}
default:
MVM_exception_throw_adhoc(tc,
"Internal error, string corruption in iterate_gi_into_string\n");
}
result_pos += to_copy;
if (result_graphs <= result_pos || !MVM_string_gi_has_more_strands_rep(tc, gi)) {
break;
}
MVM_string_gi_next_strand_rep(tc, gi);
}
}
else {
MVMStringIndex result_pos = 0;
result->body.storage_type = MVM_STRING_GRAPHEME_32;
result32 = result->body.storage.blob_32 =
result_graphs ? MVM_malloc(result_graphs * sizeof(MVMGrapheme32)) : NULL;
while (1) {
MVMStringIndex strand_len = MVM_string_gi_graphs_left_in_strand(tc, gi);
MVMStringIndex to_copy = result_graphs - result_pos < strand_len
? result_graphs - result_pos
: strand_len;
switch (MVM_string_gi_blob_type(tc, gi)) {
case MVM_STRING_GRAPHEME_8:
case MVM_STRING_GRAPHEME_ASCII: {
MVMGrapheme8 *active_blob =
MVM_string_gi_active_blob_8_pos(tc, gi);
MVMGrapheme32 *result_blob32 = result32 + result_pos;
MVMStringIndex i;
MVM_VECTORIZE_LOOP
for (i = 0; i < to_copy; i++) {
result_blob32[i] = active_blob[i];
}
break;
}
case MVM_STRING_GRAPHEME_32: {
memcpy(
result32 + result_pos,
MVM_string_gi_active_blob_32_pos(tc, gi),
to_copy * sizeof(MVMGrapheme32)
);
break;
}
default:
MVM_exception_throw_adhoc(tc,
"Internal error, string corruption in iterate_gi_into_string\n");
}
result_pos += to_copy;
if (result_graphs <= result_pos || !MVM_string_gi_has_more_strands_rep(tc, gi)) {
break;
}
MVM_string_gi_next_strand_rep(tc, gi);
}
}
}
#define copy_strands_memcpy(BLOB_TYPE, SIZEOF_TYPE, STORAGE_TYPE) { \
result->body.storage.BLOB_TYPE = MVM_malloc(sizeof(SIZEOF_TYPE) * MVM_string_graphs_nocheck(tc, orig)); \
for (i = 0; i < orig->body.num_strands; i++) { \
size_t graphs_this_strand = orig->body.storage.strands[i].end - orig->body.storage.strands[i].start; \
/* If it's 8bit format and there's only one grapheme */ \
if ((STORAGE_TYPE == MVM_STRING_GRAPHEME_ASCII || STORAGE_TYPE == MVM_STRING_GRAPHEME_8) && graphs_this_strand == 1) { \
/* If there are not repetitions we can directly set the grapheme */ \
if (!orig->body.storage.strands[i].repetitions) \
result->body.storage.BLOB_TYPE[graphs_so_far] = orig->body.storage.strands[i].blob_string->body.storage.BLOB_TYPE[orig->body.storage.strands[i].start]; \
/* Otherwise, use memset for the correct number of repetitions */ \
else { \
graphs_this_strand += orig->body.storage.strands[i].repetitions; \
memset(graphs_so_far + result->body.storage.BLOB_TYPE, \
orig->body.storage.strands[i].blob_string->body.storage.BLOB_TYPE[orig->body.storage.strands[i].start], \
graphs_this_strand \
); \
} \
graphs_so_far += graphs_this_strand; \
} \
else { \
int j = 0; \
for (; j <= orig->body.storage.strands[i].repetitions; j++) { \
memcpy(graphs_so_far + result->body.storage.BLOB_TYPE, \
orig->body.storage.strands[i].blob_string->body.storage.BLOB_TYPE + orig->body.storage.strands[i].start, \
sizeof(SIZEOF_TYPE) * graphs_this_strand \
); \
graphs_so_far += graphs_this_strand; \
} \
} \
} \
}
/* Collapses a bunch of strands into a single blob string. */
static MVMString * collapse_strands(MVMThreadContext *tc, MVMString *orig) {
MVMString *result = NULL;
size_t graphs_so_far = 0;
/* If it's not a strand, just return it */
if (orig->body.storage_type != MVM_STRING_STRAND)
return orig;
/* If the original string is a STRAND and all the composite strands are
* of the same type, then we will collapse it using memcpy instead of
* using a grapheme iterator. */
else {
size_t i;
MVMint32 common_storage_type = orig->body.storage.strands[0].blob_string->body.storage_type;
MVMROOT(tc, orig, {
result = (MVMString *)MVM_repr_alloc_init(tc, tc->instance->VMString);
result->body.num_graphs = MVM_string_graphs(tc, orig);
for (i = 1; i < orig->body.num_strands; i++) {
if (common_storage_type != orig->body.storage.strands[i].blob_string->body.storage_type) {
common_storage_type = -1;
break;
}
}
result->body.storage_type = common_storage_type;
switch (common_storage_type) {
case MVM_STRING_GRAPHEME_32:
copy_strands_memcpy(blob_32, MVMGrapheme32, MVM_STRING_GRAPHEME_32);
break;
case MVM_STRING_GRAPHEME_ASCII:
case MVM_STRING_GRAPHEME_8:
copy_strands_memcpy(blob_8, MVMGrapheme8, MVM_STRING_GRAPHEME_8);
break;
default: {
MVMGraphemeIter gi;
MVM_string_gi_init(tc, &gi, orig);
iterate_gi_into_string(tc, &gi, result, orig, 0);
}
}
});
}
#if (MVM_DEBUG_STRANDS || MVM_DEBUG_NFG)
if (!MVM_string_equal(tc, result, orig))
MVM_exception_throw_adhoc(tc, "result and original were not eq in collapse_strands");
#endif
return result;
}
/* Takes a string that is no longer in NFG form after some concatenation-style
* operation, and returns a new string that is in NFG. Note that we could do a
* much, much, smarter thing in the future that doesn't involve all of this
* copying and allocation and re-doing the whole string, but cases like this
* should be fairly rare anyway, so go with simplicity for now. */
static MVMString * re_nfg(MVMThreadContext *tc, MVMString *in) {
MVMNormalizer norm;
MVMCodepointIter ci;
MVMint32 ready;
MVMString *out = NULL;
MVMuint32 bufsize = in->body.num_graphs;
/* Create the output buffer. We used to believe it can't ever be bigger
* than the initial estimate, but utf8-c8 showed us otherwise. */
MVMGrapheme32 *out_buffer = MVM_malloc(bufsize * sizeof(MVMGrapheme32));
MVMint64 out_pos = 0;
/* Iterate codepoints and normalizer. */
MVM_unicode_normalizer_init(tc, &norm, MVM_NORMALIZE_NFG);
/* Codepoint iterator that passes back utf8-c8 graphemes unchanged */
MVM_string_ci_init(tc, &ci, in, 0, 1);
while (MVM_string_ci_has_more(tc, &ci)) {
MVMGrapheme32 g;
ready = MVM_unicode_normalizer_process_codepoint_to_grapheme(tc, &norm, MVM_string_ci_get_codepoint(tc, &ci), &g);
if (ready) {
if (out_pos + ready > bufsize) {
/* Doubling up the buffer size seems excessive, so just
* add a generous amount of storage */
bufsize += ready + 32;
out_buffer = MVM_realloc(out_buffer, bufsize * sizeof(MVMGrapheme32));
}
out_buffer[out_pos++] = g;
while (--ready > 0) {
out_buffer[out_pos++] = MVM_unicode_normalizer_get_grapheme(tc, &norm);
}
}
}
MVM_unicode_normalizer_eof(tc, &norm);
ready = MVM_unicode_normalizer_available(tc, &norm);
if (out_pos + ready > bufsize) {
bufsize += ready + 1;
out_buffer = MVM_realloc(out_buffer, bufsize * sizeof(MVMGrapheme32));
}
while (ready--) {
out_buffer[out_pos++] = MVM_unicode_normalizer_get_grapheme(tc, &norm);
}
MVM_unicode_normalizer_cleanup(tc, &norm);
/* Build result string. */
out = (MVMString *)MVM_repr_alloc_init(tc, tc->instance->VMString);
out->body.storage.blob_32 = out_buffer;
out->body.storage_type = MVM_STRING_GRAPHEME_32;
out->body.num_graphs = out_pos;
return out;
}
/* Returns nonzero if two substrings are equal, doesn't check bounds */
MVMint64 MVM_string_substrings_equal_nocheck(MVMThreadContext *tc, MVMString *a,
MVMint64 starta, MVMint64 length, MVMString *b, MVMint64 startb) {
MVMint64 i;
/* Fast paths when storage types are identical. */
switch (a->body.storage_type) {
case MVM_STRING_GRAPHEME_32:
if (b->body.storage_type == MVM_STRING_GRAPHEME_32)
return 0 == memcmp(
a->body.storage.blob_32 + starta,
b->body.storage.blob_32 + startb,
length * sizeof(MVMGrapheme32));
break;
case MVM_STRING_GRAPHEME_ASCII:
case MVM_STRING_GRAPHEME_8:
if (b->body.storage_type == MVM_STRING_GRAPHEME_ASCII ||
b->body.storage_type == MVM_STRING_GRAPHEME_8)
return 0 == memcmp(
a->body.storage.blob_8 + starta,
b->body.storage.blob_8 + startb,
length);
break;
}
/* If both are flat, use MVM_string_get_grapheme_at_nocheck on both for speed */
if (a->body.storage_type != MVM_STRING_STRAND && b->body.storage_type != MVM_STRING_STRAND) {
for (i = 0; i < length; i++)
if (MVM_string_get_grapheme_at_nocheck(tc, a, starta + i)
!= MVM_string_get_grapheme_at_nocheck(tc, b, startb + i))
return 0;
return 1;
}
else if (a->body.storage_type == MVM_STRING_STRAND && b->body.storage_type == MVM_STRING_STRAND) {
MVMGraphemeIter gia, gib;
/* Normal path, for the rest of the time. */
MVM_string_gi_init(tc, &gia, a);
MVM_string_gi_init(tc, &gib, b);
/* Move the grapheme iterator if start is not 0 */
if (starta) MVM_string_gi_move_to(tc, &gia, starta);
if (startb) MVM_string_gi_move_to(tc, &gib, startb);
for (i = 0; i < length; i++)
if (MVM_string_gi_get_grapheme(tc, &gia) != MVM_string_gi_get_grapheme(tc, &gib))
return 0;
return 1;
}
else {
MVMGraphemeIter gi_y;
MVMString *y = NULL, *z = NULL;
MVMint64 starty, startz;
if (a->body.storage_type == MVM_STRING_STRAND) {
y = a; z = b;
starty = starta; startz = startb;
}
else {
y = b; z = a;
starty = startb; startz = starta;
}
MVM_string_gi_init(tc, &gi_y, y);
if (starty) MVM_string_gi_move_to(tc, &gi_y, starty);
for (i = 0; i < length; i++)
if (MVM_string_gi_get_grapheme(tc, &gi_y) != MVM_string_get_grapheme_at_nocheck(tc, z, startz + i))
return 0;
return 1;
}
}
static MVMint64 MVM_string_memmem_grapheme32 (MVMThreadContext *tc, MVMGrapheme32 *H_blob32, MVMGrapheme32 *n_blob32, MVMint64 H_start, MVMStringIndex H_graphs, MVMStringIndex n_graphs) {
MVMGrapheme32 * rtrn = memmem_uint32(H_blob32 + H_start, H_graphs - H_start, n_blob32, n_graphs);
return rtrn == NULL ? -1 : rtrn - H_blob32;
}
static MVMint64 MVM_string_memmem_grapheme32str (MVMThreadContext *tc, MVMString *Haystack, MVMString *needle, MVMint64 H_start, MVMStringIndex H_graphs, MVMStringIndex n_graphs) {
MVMGrapheme32 *needle_buf = NULL;
MVMint64 rtrn;
if (needle->body.storage_type != MVM_STRING_GRAPHEME_32) {
MVMStringIndex i;
MVMGraphemeIter n_gi;
needle_buf = MVM_malloc(needle->body.num_graphs * sizeof(MVMGrapheme32));
if (needle->body.storage_type != MVM_STRING_GRAPHEME_8) MVM_string_gi_init(tc, &n_gi, needle);
for (i = 0; i < needle->body.num_graphs; i++) {
needle_buf[i] = needle->body.storage_type == MVM_STRING_GRAPHEME_8 ? needle->body.storage.blob_8[i] : MVM_string_gi_get_grapheme(tc, &n_gi);
}
}
rtrn = MVM_string_memmem_grapheme32(tc, Haystack->body.storage.blob_32, needle_buf ? needle_buf : needle->body.storage.blob_32, H_start, H_graphs, n_graphs);
if (needle_buf) MVM_free(needle_buf);
return rtrn;
}
/* Returns the location of one string in another or -1 */
MVMint64 MVM_string_index(MVMThreadContext *tc, MVMString *Haystack, MVMString *needle, MVMint64 start) {
size_t index = (size_t)start;
MVMStringIndex H_graphs, n_graphs;
MVM_string_check_arg(tc, Haystack, "index search target");
MVM_string_check_arg(tc, needle, "index search term");
H_graphs = MVM_string_graphs_nocheck(tc, Haystack);
n_graphs = MVM_string_graphs_nocheck(tc, needle);
if (!n_graphs)
return start <= H_graphs ? start : -1; /* the empty string is in any other string */
if (!H_graphs)
return -1;
if (start < 0 || H_graphs <= start)
return -1;
if (H_graphs < n_graphs || n_graphs < 1)
return -1;
/* Fast paths when storage types are identical. Uses memmem function, which
* uses Knuth-Morris-Pratt algorithm on Linux and on others
* Crochemore+Perrin two-way string matching */
switch (Haystack->body.storage_type) {
case MVM_STRING_GRAPHEME_32:
if (needle->body.storage_type == MVM_STRING_GRAPHEME_32 || needle->body.num_graphs < 100) {
return MVM_string_memmem_grapheme32str(tc, Haystack, needle, start, H_graphs, n_graphs);
}
break;
case MVM_STRING_GRAPHEME_8:
if (needle->body.storage_type == MVM_STRING_GRAPHEME_8 || needle->body.num_graphs < 100) {
void *mm_return_8 = NULL;
MVMGrapheme8 *needle_buf = NULL;
if (needle->body.storage_type != MVM_STRING_GRAPHEME_8) {
MVMStringIndex i;
MVMGraphemeIter n_gi;
needle_buf = MVM_malloc(needle->body.num_graphs * sizeof(MVMGrapheme8));
if (needle->body.storage_type != MVM_STRING_GRAPHEME_32) MVM_string_gi_init(tc, &n_gi, needle);
for (i = 0; i < needle->body.num_graphs; i++) {
MVMGrapheme32 g = needle->body.storage_type == MVM_STRING_GRAPHEME_32
? needle->body.storage.blob_32[i]
: MVM_string_gi_get_grapheme(tc, &n_gi);
/* Haystack is 8 bit, needle is 32 bit. if we encounter a non8bit grapheme
* it's impossible to match */
if (!can_fit_into_8bit(g)) {
MVM_free(needle_buf);
return -1;
}
needle_buf[i] = g;
}
}
mm_return_8 = MVM_memmem(
Haystack->body.storage.blob_8 + start, /* start position */
(H_graphs - start) * sizeof(MVMGrapheme8), /* length of Haystack from start position to end */
needle_buf ? needle_buf : needle->body.storage.blob_8, /* needle start */
n_graphs * sizeof(MVMGrapheme8) /* needle length */
);
if (needle_buf) MVM_free(needle_buf);
if (mm_return_8 == NULL)
return -1;
else
return (MVMGrapheme8*)mm_return_8 - Haystack->body.storage.blob_8;
}
break;
}
/* Minimal code version for needles of size 1 */
if (n_graphs == 1) {
MVMGraphemeIter H_gi;
MVMGrapheme32 n_g = MVM_string_get_grapheme_at_nocheck(tc, needle, 0);
MVM_string_gi_init(tc, &H_gi, Haystack);
if (index) MVM_string_gi_move_to(tc, &H_gi, index);
while (index < H_graphs) {
if (n_g == MVM_string_gi_get_grapheme(tc, &H_gi))
return (MVMint64)index;
index++;
}
}
else if (n_graphs <= MVM_string_KMP_max_pattern_length)
return knuth_morris_pratt_string_index(tc, needle, Haystack, start);
else {
int is_gic = Haystack->body.storage_type == MVM_STRING_STRAND ? 1 : 0;
void *Hs_or_gic = Haystack;
/* If Haystack is a strand allocate space for a MVMGraphemeIter_cached
* and initialize it */
if (is_gic) {
Hs_or_gic = alloca(sizeof(MVMGraphemeIter_cached));
MVM_string_gi_cached_init(tc, Hs_or_gic, Haystack, start);
}
/* For needles > MVM_string_KMP_max_pattern_length we must revert to brute force for now.
* Eventually we can implement brute force after it matches the whole needle OR
* allocate more space for the pattern on reaching the end of the pattern */
while (index <= H_graphs - n_graphs) {
if (string_equal_at_ignore_case_INTERNAL_loop(tc, Hs_or_gic, needle, index, H_graphs, n_graphs, 0, 0, is_gic) != -1)
return (MVMint64)index;
index++;
}
}
return -1;
}
/* Returns the location of one string in another or -1 */
MVMint64 MVM_string_index_from_end(MVMThreadContext *tc, MVMString *Haystack, MVMString *needle, MVMint64 start) {
MVMint64 result = -1;
size_t index;
MVMStringIndex H_graphs, n_graphs;
MVM_string_check_arg(tc, Haystack, "rindex search target");
MVM_string_check_arg(tc, needle, "rindex search term");
H_graphs = MVM_string_graphs_nocheck(tc, Haystack);
n_graphs = MVM_string_graphs_nocheck(tc, needle);
if (!n_graphs) {
if (0 <= start)
return start <= H_graphs ? start : -1; /* the empty string is in any other string */
else
return H_graphs; /* no start, so return end */
}
if (!H_graphs)
return -1;
if (H_graphs < n_graphs || n_graphs < 1)
return -1;
if (start == -1)
start = H_graphs - n_graphs;
if (start < 0 || H_graphs <= start)
/* maybe return -1 instead? */
MVM_exception_throw_adhoc(tc, "index start offset out of range");
index = start;
if (H_graphs < index + n_graphs) {
index = H_graphs - n_graphs;
}
/* brute force for now. horrible, yes. halp. */
do {
if (MVM_string_substrings_equal_nocheck(tc, needle, 0, n_graphs, Haystack, index)) {
result = (MVMint64)index;
break;
}
} while (0 < index--);
return result;
}
/* Returns a substring of the given string */
MVMString * MVM_string_substring(MVMThreadContext *tc, MVMString *a, MVMint64 offset, MVMint64 length) {
MVMString *result;
MVMint64 start_pos, end_pos;
MVMint64 agraphs;
MVM_string_check_arg(tc, a, "substring");
/* convert to signed to avoid implicit arithmetic conversions */
agraphs = (MVMint64)MVM_string_graphs_nocheck(tc, a);
/* -1 signifies go to the end of the string; anything less is a bug */
if (length < -1)
MVM_exception_throw_adhoc(tc, "Substring length (%"PRId64") cannot be negative", length);
/* negative offsets count from the end */
start_pos = offset < 0 ? offset + agraphs : offset;
end_pos = length == -1 ? agraphs : start_pos + length;
/* return an empty string if start_pos is out of bounds but positive */
if (agraphs < start_pos) {
start_pos = 0;
end_pos = 0;
}
if (end_pos < 0)
MVM_exception_throw_adhoc(tc, "Substring end (%"PRId64") cannot be less than 0", end_pos);
/* Ensure we're within bounds. */
if (start_pos < 0)
start_pos = 0;
if (agraphs < end_pos)
end_pos = agraphs;
/* Check trivial cases: empty string and whole string. */
if (start_pos == end_pos)
return tc->instance->str_consts.empty;
if (start_pos == 0 && end_pos == agraphs)
return a;
/* Construct a result; how we efficiently do so will vary based on the
* input string. */
MVMROOT(tc, a, {
result = (MVMString *)MVM_repr_alloc_init(tc, tc->instance->VMString);
result->body.num_graphs = end_pos - start_pos;
if (a->body.storage_type != MVM_STRING_STRAND) {
/* It's some kind of buffer. Construct a strand view into it. */
result->body.storage_type = MVM_STRING_STRAND;
result->body.storage.strands = allocate_strands(tc, 1);
result->body.num_strands = 1;
result->body.storage.strands[0].blob_string = a;
result->body.storage.strands[0].start = start_pos;
result->body.storage.strands[0].end = end_pos;
result->body.storage.strands[0].repetitions = 0;
}
else if (a->body.num_strands == 1 && a->body.storage.strands[0].repetitions == 0) {
/* Single strand string; quite possibly already a substring. We'll
* just produce an updated view. */
MVMStringStrand *orig_strand = &(a->body.storage.strands[0]);
result->body.storage_type = MVM_STRING_STRAND;
result->body.storage.strands = allocate_strands(tc, 1);
result->body.num_strands = 1;
result->body.storage.strands[0].blob_string = orig_strand->blob_string;
result->body.storage.strands[0].start = orig_strand->start + start_pos;
result->body.storage.strands[0].end = orig_strand->start + end_pos;
result->body.storage.strands[0].repetitions = 0;
}
else {
/* Produce a new blob string, collapsing the strands. */
MVMGraphemeIter gi;
MVM_string_gi_init(tc, &gi, a);
MVM_string_gi_move_to(tc, &gi, start_pos);
iterate_gi_into_string(tc, &gi, result, a, start_pos);
}
});
STRAND_CHECK(tc, result);
return result;
}
MVMString * MVM_string_replace(MVMThreadContext *tc, MVMString *original, MVMint64 start, MVMint64 count, MVMString *replacement) {
/* XXX this could probably be done more efficiently directly. */
MVMString *first_part = NULL;
MVMString *rest_part = NULL;
MVMString *result = NULL;
MVM_gc_root_temp_push(tc, (MVMCollectable **)&replacement);
MVM_gc_root_temp_push(tc, (MVMCollectable **)&original);
MVM_gc_root_temp_push(tc, (MVMCollectable **)&first_part);
first_part = MVM_string_substring(tc, original, 0, start);
rest_part = MVM_string_substring(tc, original, start + count, -1);
rest_part = MVM_string_concatenate(tc, replacement, rest_part);
result = MVM_string_concatenate(tc, first_part, rest_part);
STRAND_CHECK(tc, result);
NFG_CHECK(tc, result, "MVM_string_replace");
MVM_gc_root_temp_pop_n(tc, 3);
return result;
}
static MVMString * string_from_strand_at_index(MVMThreadContext *tc, MVMString *a, MVMuint16 index) {
MVMStringStrand *ss = &(a->body.storage.strands[index]);
return MVM_string_substring(tc, ss->blob_string, ss->start, ss->end - ss->start);
}
static MVMuint16 final_strand_match_with_repetition_count(MVMThreadContext *tc, MVMString *a, MVMString *b) {
if (a->body.storage_type == MVM_STRING_STRAND) {
MVMStringStrand *sa = &(a->body.storage.strands[a->body.num_strands - 1]);
/* If the final strand of a eq b, we'll just increment the final strand of a's repetitions. */
if (sa->end - sa->start == MVM_string_graphs_nocheck(tc, b)) {
if (MVM_string_equal_at(tc, sa->blob_string, b, sa->start))
return 1;
}
/* If the final strand of a eq the first (and only) strand of b, we'll just add b's repetitions
* (plus 1 for the strand itself) to the final strand of a's repetitions. */
else if (b->body.storage_type == MVM_STRING_STRAND && b->body.num_strands == 1) {
MVMStringStrand *sb = &(b->body.storage.strands[0]);
if (sa->end - sa->start == sb->end - sb->start) {
MVMString *a_strand, *b_strand;
MVMROOT2(tc, a, b, {
a_strand = string_from_strand_at_index(tc, a, a->body.num_strands - 1);
b_strand = string_from_strand_at_index(tc, b, 0);
});
if (MVM_string_equal(tc, a_strand, b_strand))
return b->body.storage.strands[0].repetitions + 1;
}
}
}
return 0;
}
/* Append one string to another. */
MVMString * MVM_string_concatenate(MVMThreadContext *tc, MVMString *a, MVMString *b) {
MVMString *result = NULL, *renormalized_section = NULL;
int renormalized_section_graphs = 0, consumed_a = 0, consumed_b = 0;
MVMuint32 agraphs, bgraphs;
MVMuint64 total_graphs;
int lost_strands = 0;
int is_concat_stable = 0;
int index_ss_b;
MVMuint16 matching_repetition_count;
MVM_string_check_arg(tc, a, "concatenate");
MVM_string_check_arg(tc, b, "concatenate");
/* Simple empty-string cases. */
agraphs = MVM_string_graphs_nocheck(tc, a);
if (agraphs == 0)
return b;
bgraphs = MVM_string_graphs_nocheck(tc, b);
if (bgraphs == 0)
return a;
is_concat_stable = MVM_nfg_is_concat_stable(tc, a, b);
/* If is_concat_stable equals 0 and a and b are not repetitions. */
if (is_concat_stable == 0 && !(a->body.storage_type == MVM_STRING_STRAND && a->body.storage.strands[a->body.num_strands - 1].repetitions)
&& !(b->body.storage_type == MVM_STRING_STRAND && b->body.storage.strands[0].repetitions)) {
MVMCodepoint last_a_first_b[2] = {
MVM_string_get_grapheme_at_nocheck(tc, a, a->body.num_graphs - 1),
MVM_string_get_grapheme_at_nocheck(tc, b, 0)
};
MVMROOT2(tc, a, b, {
/* If both are not synthetics, we can can pass those values unchanged
* instead of iterating by codepoint */
if (0 <= last_a_first_b[0] && 0 <= last_a_first_b[1]) {
renormalized_section = MVM_unicode_codepoints_c_array_to_nfg_string(tc, last_a_first_b, 2);
consumed_a = 1; consumed_b = 1;
}
else {
MVMCodepointIter last_a_ci;
MVMCodepointIter first_b_ci;
MVMuint32 a_codes = MVM_string_grapheme_ci_init(tc, &last_a_ci, last_a_first_b[0], 1);
MVMuint32 b_codes = MVM_string_grapheme_ci_init(tc, &first_b_ci, last_a_first_b[1], 1);
/* MSVC doesn't allow variable length arrays so use alloca to allocate onto the stack */
MVMCodepoint *last_a_first_b_codes = alloca((a_codes + b_codes) * sizeof(MVMCodepoint));
MVMuint32 i = 0;
for (; MVM_string_grapheme_ci_has_more(tc, &last_a_ci); i++) {
last_a_first_b_codes[i] = MVM_string_grapheme_ci_get_codepoint(tc, &last_a_ci);
}
for (; MVM_string_grapheme_ci_has_more(tc, &first_b_ci); i++) {
last_a_first_b_codes[i] = MVM_string_grapheme_ci_get_codepoint(tc, &first_b_ci);
}
renormalized_section = MVM_unicode_codepoints_c_array_to_nfg_string(tc, last_a_first_b_codes, a_codes + b_codes);
consumed_a = 1; consumed_b = 1;
}
});
if (renormalized_section) {
if (agraphs == consumed_a && bgraphs == consumed_b) {
NFG_CHECK_CONCAT(tc, renormalized_section, a, b, "renormalized_section");
return renormalized_section;
}
renormalized_section_graphs = MVM_string_graphs_nocheck(tc, renormalized_section);
}
}
/* Total size of the resulting string can't be bigger than an MVMString is allowed to be. */
total_graphs = (MVMuint64)agraphs + (MVMuint64)bgraphs;
if (MAX_GRAPHEMES < total_graphs)
MVM_exception_throw_adhoc(tc,
"Can't concatenate strings, required number of graphemes %"PRIu64" > max allowed of %lld",
total_graphs, MAX_GRAPHEMES);
/* Otherwise, we'll assemble a result string. */
MVMROOT4(tc, a, b, renormalized_section, result, {
/* Allocate it. */
result = (MVMString *)MVM_repr_alloc_init(tc, tc->instance->VMString);
/* Total graphemes is trivial; just total up inputs. */
result->body.num_graphs = (MVMuint32)total_graphs;
/* Result string will be made of strands. */
result->body.storage_type = MVM_STRING_STRAND;
/* Detect the wonderful case where we're repeatedly concating the same
* string again and again, and thus can just bump a repetition. */
if (is_concat_stable == 1 && (matching_repetition_count = final_strand_match_with_repetition_count(tc, a, b))) {
/* We have it; just copy the strands to a new string and bump the
* repetitions count of the last one. */
result->body.storage.strands = allocate_strands(tc, a->body.num_strands);
copy_strands(tc, a, 0, result, 0, a->body.num_strands);
result->body.storage.strands[a->body.num_strands - 1].repetitions += matching_repetition_count;
result->body.num_strands = a->body.num_strands;
}
/* Otherwise, construct a new strand string. */
else {
/* See if we have too many strands between the two. If so, we will
* collapse the biggest side. */
MVMuint16 strands_a = a->body.storage_type == MVM_STRING_STRAND
? a->body.num_strands
: 1;
MVMuint16 strands_b = b->body.storage_type == MVM_STRING_STRAND
? b->body.num_strands
: 1;
MVMString *effective_a = a;
MVMString *effective_b = b;
if (MVM_STRING_MAX_STRANDS < strands_a + strands_b) {
MVMROOT(tc, result, {
if (strands_b <= strands_a) {
effective_a = collapse_strands(tc, effective_a);
strands_a = 1;
}
else {
effective_b = collapse_strands(tc, effective_b);
strands_b = 1;
}
});
}
/* Assemble the result. */
result->body.num_strands = strands_a + strands_b + (renormalized_section_graphs ? 1 : 0);
result->body.storage.strands = allocate_strands(tc, result->body.num_strands);
/* START 1 */
if (effective_a->body.storage_type == MVM_STRING_STRAND) {
copy_strands(tc, effective_a, 0, result, 0, strands_a);
}
else {
int index_ss_a = 0;
MVMStringStrand *ss_a = &(result->body.storage.strands[index_ss_a]);
ss_a->blob_string = effective_a;
ss_a->start = 0;
ss_a->end = effective_a->body.num_graphs;
ss_a->repetitions = 0;
}
if (renormalized_section) {
int index_ss_re;
int index_ss_a = strands_a - 1;
/* Tweak the end of the last strand of string a. Since if a is made up of multiple strands, we can't just refer to index 0 and instead erfer to strands_a - 1 */
MVMStringStrand *ss_a = &(result->body.storage.strands[index_ss_a]);
MVMStringStrand *ss_re = NULL;
ss_a->end -= consumed_a;
/* If the strands ends up to be zero length we need to reduce the number of strand_index and also incease lost_strands so the next operation writes over it */
if (ss_a->start == ss_a->end)
lost_strands++;
/* END 1 */
/* START 1.5 (only triggered in some cases) */
index_ss_re = strands_a - lost_strands;
ss_re = &(result->body.storage.strands[index_ss_re]);
/* Add the renormalized section in as a strand */
ss_re->blob_string = renormalized_section;
ss_re->start = 0;
ss_re->end = renormalized_section->body.num_graphs;
ss_re->repetitions = 0;
if (ss_re->start == ss_re->end) {
MVM_exception_throw_adhoc(tc, "Unexpected error in concatenation: renormalized_section is 0 graphemes.\n");
/* renormalized_section should always be at least one grapheme
* in length so throw if it does not (zero length is an error
* we shouldn't lost_strands++ unlike the other strands */
}
/* END 1.5 */
}
/* START 2 */
index_ss_b = strands_a - lost_strands + (renormalized_section_graphs ? 1 : 0 );
if (effective_b->body.storage_type == MVM_STRING_STRAND) {