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Optimise space handling in jsync loader
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@sorear
sorear committed Nov 17, 2010
1 parent bdf7346 commit b9ee30f
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Showing 2 changed files with 65 additions and 65 deletions.
34 changes: 18 additions & 16 deletions lib/Cursor.cs
View file
Expand Up @@ -1439,21 +1439,6 @@ public class Lexer {
return ret;
}

// s1 must not have embedded nuls
private static unsafe bool StartsWithInvariant(string s1, string s2) {
fixed (char* st1 = s1) {
char* p1 = st1;
fixed (char* st2 = s2) {
char* p2 = st2;
while (*p1 != '\0' && *p1 == *p2) {
p1++;
p2++;
}
return (*p1 == '\0');
}
}
}

public static DynObject[] ResolveProtoregex(LexerCache lc,
string name) {
DynObject[] ret;
Expand Down Expand Up @@ -1482,7 +1467,7 @@ public class Lexer {
if (proto != k.Can(name))
continue;
foreach (KeyValuePair<string,IP6> o in k.ord_methods) {
if (!StartsWithInvariant(filter, o.Key))
if (!Utils.StartsWithInvariant(filter, o.Key))
continue;
if (cursor_class.Can(o.Key) == o.Value) {
raword.Add((DynObject) o.Value);
Expand All @@ -1495,3 +1480,20 @@ public class Lexer {
return ret;
}
}

public class Utils {
// s1 must not have embedded nuls
public static unsafe bool StartsWithInvariant(string s1, string s2) {
fixed (char* st1 = s1) {
char* p1 = st1;
fixed (char* st2 = s2) {
char* p2 = st2;
while (*p1 != '\0' && *p1 == *p2) {
p1++;
p2++;
}
return (*p1 == '\0');
}
}
}
}
96 changes: 47 additions & 49 deletions lib/JSYNC.cs
View file
Expand Up @@ -205,16 +205,20 @@ public class JsyncReader {
const int ALIAS = 2;
const int DIRECTIVE = 3;

void SkipWhite(bool more) {
// most parsers are expected to skip white before
char SkipWhite(bool more) {
while (ix != from.Length) {
char ch = from[ix];
if (ch == ' ' || ch == '\r' || ch == '\t' || ch == '\n')
ix++;
else
break;
}
if (more && ix == from.Length)
Err("Unexpected end of text");
if (more) {
if (ix == from.Length)
Err("Unexpected end of text");
return from[ix];
} else { return '\0'; }
}

void Err(string s) {
Expand All @@ -227,17 +231,26 @@ public class JsyncReader {
ix += s.Length;
}

void SkipCharWS(char c) {
if (SkipWhite(true) != c)
Err("Missing token " + c);
ix++;
}

void SkipChar(char c) {
if (from[ix] != c)
Err("Missing token " + c);
ix++;
}

static Variable BoxRW(object o, DynMetaObject mo) {
DynObject dyo = new DynObject(mo);
dyo.slots[0] = o;
return Kernel.NewRWScalar(Kernel.AnyMO, dyo);
}

Variable GetObj() {
SkipWhite(true);
char first = from[ix];

switch(first) {
switch(SkipWhite(true)) {
case '{':
return GetFromHash();
case '[':
Expand All @@ -260,8 +273,7 @@ public class JsyncReader {
}

string GetJsonString() {
SkipWhite(true);
SkipToken("\"");
SkipCharWS('"');

StringBuilder sb = new StringBuilder();
while (true) {
Expand Down Expand Up @@ -423,19 +435,17 @@ public class JsyncReader {
}

Variable GetFromArray() {
SkipToken("[");
SkipWhite(true);
SkipCharWS('[');
VarDeque kids = new VarDeque();
DynObject obj = new DynObject(Kernel.ArrayMO);
obj.SetSlot("items", kids);
obj.SetSlot("rest", new VarDeque());
bool comma = false;
string a_tag = null;

if (from[ix] == '"') {
if (SkipWhite(true) == '"') {
GetString();
comma = true;
SkipWhite(true);
}

if (comma) {
Expand All @@ -448,25 +458,22 @@ public class JsyncReader {
}

while(true) {
if (from[ix] == ']') break;
if (SkipWhite(true) == ']') break;
if (comma) {
SkipToken(",");
SkipWhite(true);
SkipChar(',');
}
kids.Push(GetObj());
SkipWhite(true);
comma = true;
}
SkipToken("]");
SkipCharWS(']');
if (a_tag != null)
Err("Typed arrays are NYI in Niecza Perl 6");
return Kernel.NewRWScalar(Kernel.AnyMO, obj);
}

string GetSimpleStringValue() {
SkipToken(":");
SkipWhite(true);
if (from[ix] != '"')
SkipCharWS(':');
if (SkipWhite(true) != '"')
Err("Expected a simple scalar");
GetString();
if (s_content_type != SCALAR || s_tag != null || s_anchor != null)
Expand All @@ -475,7 +482,7 @@ public class JsyncReader {
}

Variable GetFromHash() {
SkipToken("{");
SkipCharWS('{');
// we can't make any assumptions about ordering here, as JSON
// emitters can blindly reorder hashes
string h_tag = null;
Expand All @@ -486,15 +493,13 @@ public class JsyncReader {
bool comma = false;

while(true) {
SkipWhite(true);
if (from[ix] == '}') break;
if (SkipWhite(true) == '}') break;
if (comma) {
SkipToken(",");
SkipWhite(true);
SkipChar(',');
}
comma = true;
SkipWhite(false);
GetString();
SkipWhite(true);
if (s_content_type == NONE && s_anchor == null && s_tag == "") {
if (h_tag != null)
Err("Tag specified twice");
Expand All @@ -510,9 +515,8 @@ public class JsyncReader {
if (h_key_ind == null) h_key_ind = new Dictionary<string,string>();
if (h_key_ind.ContainsKey(k1))
Err("Key alias &" + k1 + " specified twice");
SkipToken(":");
SkipWhite(true);
if (from[ix] != '"')
SkipCharWS(':');
if (SkipWhite(true) != '"')
Err("Non-scalar hash keys NYI in Niecza Perl 6");
GetString();
if (s_tag != null || s_anchor != null || s_content_type != SCALAR)
Expand All @@ -523,22 +527,20 @@ public class JsyncReader {
if (h_val_ind == null) h_val_ind = new Dictionary<string,Variable>();
if (h_val_ind.ContainsKey(k1))
Err("Key alias *" + k1 + " used twice");
SkipToken(":");
SkipWhite(true);
SkipCharWS(':');
h_val_ind[k1] = GetObj();
} else if (s_content_type == DIRECTIVE) {
Err("Got directive in hash key position");
} else {
if (s_tag != null || s_anchor != null)
Err("Typed hash keys NYI in Niecza Perl 6");
string k1 = s_content;
SkipToken(":");
SkipWhite(true);
SkipCharWS(':');
zyg[k1] = GetObj();
}
}

SkipToken("}");
SkipChar('}');

if (h_key_ind != null || h_val_ind != null) {
h_key_ind = h_key_ind ?? new Dictionary<string,string>();
Expand All @@ -561,7 +563,7 @@ public class JsyncReader {

Variable obj;
if (h_tag != null) {
if (!h_tag.StartsWith("!perl6/"))
if (!Utils.StartsWithInvariant("!perl6/", h_tag))
Err("Unsupported hash tag " + h_tag);
int s_cursor = 7;
IP6 p_cursor = Kernel.GlobalO;
Expand Down Expand Up @@ -662,27 +664,23 @@ public class JsyncReader {
}

Variable GetTopLevel() {
SkipWhite(true);
if (from[ix] != '[') {
if (from[ix] != '{')
char f = SkipWhite(true);
if (f != '[') {
if (f != '{')
Err("Top level item must be an aggregate");
goto bare;
}
SkipToken("[");
SkipWhite(true);
if (from[ix] != '{') goto bare;
SkipToken("{");
SkipWhite(true);
if (from[ix] != '"') goto bare;
ix++;
if (SkipWhite(true) != '{') goto bare;
ix++;
if (SkipWhite(true) != '"') goto bare;
GetString();
if (s_content_type != DIRECTIVE) goto bare;

GetDirectiveBlock();
SkipWhite(true);
SkipToken(",");
SkipCharWS(',');
Variable v = GetObj();
SkipWhite(true);
SkipToken("]");
SkipCharWS(']');
return v;

bare:
Expand Down

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